Nutrient Balance in Small Catchments of the Upland Areas of the Gumara River, Northwestern Ethiopia

Nutrient Balance in Small Catchments of the Upland Areas of the Gumara River, Northwestern Ethiopia | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Nutrient Balance in Small Catchments of the Upland Areas of the Gumara River, Northwestern Ethiopia Melese Gezie, Enyew Adgo, Habtamu Assaye, Alemayehu Wassie This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3893338/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Nutrient balance analysis provides essential information concerning the current nutrient status of the soils and used to take appropriate nutrient replenishment practices. Nutrient flows were analyzed in Enqulal watershed of Dera district, Northwestern Ethiopia in the cropping season of 2018. Direct measurement and empirical formulas were used to identifying and measuring major inputs and outputs of NPK from different land uses within the catchments. Four nutrient inputs (Mineral fertilizer, Organic fertilizer, Atmospheric deposition and Nitrogen fixation) and five nutrient outputs (Crop yield, Crop residue, Gaseous lose, Leaching and Soil erosion) leaving the catchment were directly measured to calculate the partial and full nutrient balances. The results indicated that with the exception of phosphorus, teff cropland had negative partial N and K balances. The results also showed that the partial nutrient balances in wheat cropland were observed positive only for nitrogen. The full nutrient balances for the major cropland (wheat and teff) were found to be -20.9 kg , -0.7 kg , -37.87 kg ha -1 yr -1 and -61.4 kg ,+11 kg, and -26.7 kg ha -1 yr -1 of N, P and K respectively. Generally, negative N and K full balances were found in this study for all land use/land cover. Therefore, the negative nutrient balances observed in cultivated land and other land uses indicated nutrient depletion which leads to land degradation and reduced agricultural productivity. Finally, analysis of the overall finding on nutrient balance implies that there is a need to enhance nutrient management in order to improve productivity and agricultural sustainability. Nutrient input Nutrient output Nutrient balance Lake Tana basin Figures Figure 1 Figure 2 1. INTRODUCTION Soil fertility decline is one of the main constraints of agricultural productivity in Africa. Soil nutrient balance studies in Africa show evidence of widespread nutrient mining leading to severe nutrient deficiencies. Negative nutrient balances of N and P are reported throughout the smallholder farming systems of Africa (Stoorvogel and Smaling, 1990 ). Soil degradation in the form of nutrient depletion, is a major factor for the declining of agricultural production in Ethiopia (Wassie Haile et al. , 2009). According to Gebremedhin Kiros et al. ( 2014 ), many nutrient balance studies in Ethiopia reported negative value. In many studies, partial nutrient balance at land use level are negative for the teff based farming system in the central high lands of Ethiopia. The study conducted by Van Beek et al. ( 2016 ). National averages of nutrient balances were estimated at -41 kg N, -6 kg P and − 26 kg K ha- 1 yr − 1 , which is among the highest nutrient depletion rates for sub-Saharan Africa. Soil nutrient degradation has become a major agricultural problem in central highlands of Ethiopia. It realized that food security cannot be achieved in the region without overcoming the problem of nutrient depletion. There are a number of studies which revealed that lack of plant nutrient is one of the main causes for low agricultural production and food security in Africa ( Amare Haileslassie et al., 2005 ). In the past, measurement of nutrient balances were addressed at sub-continental and national scales without addressing the large spatial variability of nutrient balances within a region and catchment level (Amare Haileslassie et al., 2005 ). Low productivity caused by soil degradation also the major problem in the study area. These factors minimize the adaptive capacity and exacerbate the vulnerability of farmers to future changes, such as: climate change and hydrological processes in the Lake Tana basin. Due to these multiple problems, it is very important to analyze the balance and monitor nutrient flows in and out from the farmlands and from the different land use type in the particular micro-catcment. 2. MATERIALS AND METHODS 2.1 Description of the Study Area The study was carried out in upper reaches of Lake Tana basin of Areb Gebeya area in northwestern Ethiopian. Specifically, the study sub-watersheds are found in Gumara watershed which is one of the major watersheds of Lake Tana basin. Gumara watershed is found in the eastern part of the Lake Tana basin. The watershed at the lake inlet is 1970 km 2 and 65% of it is gauged. It originates at the foot of Mount Guna which has an elevation of 4120m.a.s.l (Gashaw et al., 2014 ). Geographically, the particular study area, Enkulal watershed is located between 11 o 37’57”-11 o 88’9” latitude and 37 o 48’37”-37 o 48’13” longitude (Fig. 1 ). The area was selected by Land Resilience Research Team of the Bair Dar University- Institutional University Cooperation Programme(BDU-IUC) for the analysis of nutrient balance research. Table 1 below is showed the general overview of the location of the study area and site characteristics. Table 1 Study area sampling locations and site characteristics Land use land cover type Area of sample plot (ha) Latitude (N) and Longitude(E) Altitude (m) Cultivated land(wheat) 0.04 11 o 37’14’ $ 37 o 48’31’’ 2497 Cultivated land(teff) 0.09 11 o 38’13’’ $ 37 o 48’32’’ 2419 Natural forest 0.03 11 o 37’21’’ $ 37 o 48’31’’ 2476 Rehabilitated land 0.05 11 o 37’49’’ $ 37 o 48’57’’ 2487 Bad land 0.04 11 o 37’57’’ $ 37 o 48’37’’ 2480 Grazing land 0.02 11 o 37’59’’ $ 37 o 48’22’’ 2431 2.2 Climate, Agroecology, Geology and soil of the study area Agro-climatic conditions of the study area is tepid moist mid highlands. The maximum and minimum temperature of the study area is 25 o c and 18 o c respectively, and the average annual rainfall is 1250 mm. The altitude range of the kebele is 2200 to 2600 m.a.s.l. Sixty nine percent of the watershed has slopes of more than 8% and 96% is crop land. The main soil types of the study area particularly in the upland areas of the Gumara River are Nitisols, Vertisols, Gleysols, Luvisols and Cambisols (Temesgen Gashaw et al., 2014 ). 2.3 Land Use and Farming Systems The dominant land use and land cover classes in the study watershed are cultivated land, grazing land, forest (natural), Eucalyptus plantation (woodlots), bare land and rehabilitated land. The total area covered by the study watershed is estimated to be 120.47 ha, of which 51.84 ha is arable land, 16.68 ha is grazing land and 23.6 ha is forest, 15.38 ha is rehabilitated land and 0.85 ha is bare land. The topography of the area comprises 25% plain, 60% undulating, 5% gorge and valley, and 10% mountainous. The farming system in the study area is predominately crop production, mixed with animal production. Teff, finger millet, wheat, maize, barley, rice and potato are the major crops grown in the district but teff and wheat are the major crops cultivated in the study watershed (Van Beek et al., 2016 ). 2.4 Sampling Design and Sample Size In order to collect the required data needed to achieve the objectives of the research, a different data collection method through random sampling (RS) were employed. The study watershed was selected purposively as it is the study area of the BDU-IUC programme particularly the land Resilience project. From the selected kebele two micro small catchments were selected in such a way that the catchments represent the district in biophysical, agricultural and socio-economic aspects. Most importantly the watershed was selected so that they represent the main farming practices, crop varieties, socio economic status, and topographic features. Accordingly, enkulal watershed was selected from Gelawudewos kebele . This watershed has two small catchments and each catchment has different land cover classes. Sampling micro-catchments were selected to monitor nutrient flow in and out of the system and finally to analyze partial nutrient (N, P, and K) balance. 2.5 Data Collection The information required for nutrient balance analyses come from a mixture of sources. Obviously, the most precise was involving direct measurements of the amounts of nutrients transferred in and out through each factor. Nutrient outputs by crop product (OUT1), crop residue (OUT2) were considered under direct measurement in the field. Focus group discussions were conducted in the selected watershed area. Eight farmers were selected randomly from the selected watershed to collaborate in a soil fertility experiment and a household survey. This activity was used as a tool to identify major cropping systems, type of input and outputs, and crop production problems. These data were used to determine annual nutrient inflows and outflows for each plot and the farm as a whole. In case of outflow, survey data was used to know the biomass of crop residue and for what purpose they collected to their home. Finally these flows were used to compute the nutrient balance for each land use for one year (Van Beek et al., 2003 ). 2.6 Quantification of Nutrient Inputs and Outputs The information required for nutrient balance analyses come from a mixture of sources. Nutrient output by crop product (OUT1), crop residue (OUT2) and erosion (OUT5) were considered under direct measurement in the field. However, direct measurement was not possible for some inputs including wet deposition (IN3), nitrogen fixation (IN4) and outputs (leaching-OUT3, gaseous losses-OUT4). In such cases, inputs and outputs were estimated with transfer function. The amount of fertilizer applied was accounted through interviews and secondary data sources to calculate and convert the total amount of fertilizer into corresponding quantities of nutrients (Aticho et al., 2011 ). Inputs for N, P, K, primary data was obtained on type and amount of mineral fertilizer (IN1), organic inputs (IN2), whereas atmospheric deposition (IN3) and biological nitrogen fixation (IN4) were estimated by transfer function. Field observations were made on type and amount of input and output, type of cereal crop grown and their grain and residue yield were recorded. Atmospheric deposition of N was estimated as total agricultural land area multiplied by a single coefficient of N deposited per hectare. Non-symbiotic N fixation was calculated according to Lesschen et al. (2007). The nutrient (N, P and K) balances were calculated from a combination of four input and five output flows using a re-assign equation (Stoorvogel and Smaling, 1998). Quantification of the N, P and K in the input and output flows were achieved through the combination of different methods: field measurement, use of empirical quantitative relations ( i.e. transfer functions) and assumptions based on secondary data from a variety of sources (Kiros et al., 2014 ). N, P and K content was determined in laboratory following standard procedures (Aremu et al. ( 2006 ). The quantity of N, P and K added to farm in the form of different inputs were obtained by multiplying dry weight of each input material with its nutrient content. Plant litter fall was taken as an input source in the forest. N, P and K added to the soil with wet deposition (IN3) was estimated with the equation developed by Smaling et al. ( 1993 ) which is a function of mean annual rainfall (mm yr − 1 ). The mean annual rainfall (p) was obtained from the nearby meteorological stations (Arb Gebya Meteorology Station). IN3 N = 0.14P 1/2 (1) IN3 P = 0.023P 1/2 (2) IN3 K = 0.092P 1/2 (3) The percentages of total N uptake through symbiotic N fixation by leguminous crops were reported in different literature. Studies conducted in different parts in Ethiopia show that 60% of legume plant N requirement is met by symbiotic nitrogen fixation (Aticho et al., 2011 ). However, no literature was available for non-symbiotic N fixation and N-fixing trees that are left on the field. Therefore, this input was estimated on the basis of the amount of rainfall using the transfer function (Smaling et al., 1993 ) as follows:- IN4 = 0.5 + 0.1P 1/2 (4) Where, N fixed is expressed in kilograms of N per hectare and year, and P is mean annual precipitation in mm yr − 1 2.7 Quantifying outputs from farmland and other land uses Removal of harvested products (OUT1), crop residues (OUT2), leaching (OUT3), gaseous lose (OUT4) and erosion (OUT5) are usually the major pathways of nutrient losses from agricultural soils. The amount varies considerably depending on crop type, soil type, agronomic practices and plant nutrient uptake (Brady and Weil, 2008 ). ➢ Output quantification from harvested product (OUT1): $$\text{O}\text{U}\text{T}1=\sum \frac{(\text{a}\text{r}\text{e}\text{a}\times \text{n}\text{u}\text{t}\text{r}\text{i}\text{e}\text{n}\text{t} \text{c}\text{o}\text{n}\text{t}\text{e}\text{n}\text{t}\times \text{y}\text{i}\text{e}\text{l}\text{d})}{\text{T}\text{o}\text{t}\text{a}\text{l} \text{a}\text{r}\text{e}\text{a}}$$ 5 TN = Y×N = kg N ha − 1 (6) P = Y \(\times\) P = kg P ha − 1 (7) K = Y×K = kg K ha − 1 (8) Where, Y = yield (kg/ha), N = N content of crop (% harvested product); P = P content of crop (ppm harvested product), and K = K content of crop (ppm harvested product). ➢ Output quantification from crop residue/straw (OUT2) N = R \(\times\) N = (kg N ha − 1 ) (9) P = R \(\times\) P = (kg P ha − 1 ) (10) K = R \(\times\) K = (kg K ha − 1 ) (11) Where, R = amount of residues (kg/ha); N = N content of crop residues (kg N/ kilograms of harvested product); P = P content of crop residues (kg P/ kilograms of harvested product); K = K content of crop residues (kg K/ kilograms of harvested product). The amount of crop products (OUT1) and residues (OUT2) exported from farm section were determined by randomly demarcating 3 sample plots of each common crop ( teff and wheat) from the study area (each plot had 1 m 2 area). At crop maturity, crops in the sample plots were harvested, sun dried, trashed and weighed with hand held balance and composite samples had been taken for laboratory analysis. The amount of N, P and K exported by OUT1 and OUT2 were calculated by multiplying the total amount of crop product and residue exported from farm with their respective N, P and K content (Stoorvogel et al., 1993) . Substantial amounts of N and K are lost through leaching (OUT3) but not P as it strongly bounds with soil particle (Laird et al. , 2010). N and K losses through leaching were not directly measured; rather a transfer function was used (Stoorvogel and Smaling, 1990 ). OUT3N = 2.3+ (0.0021 + 0.0007 \(\times\) F).P + 0.3.IN1 + IN2-0.1 \(\times\) TNU (12) OUT3 K = (0.6+ (0.0011 + 0.002 \(\times\) F).P + 0.5. (IN1 + IN2)-0.1 \(\times\) TKU)/1.2 (13) Where, P: mean annual rainfall, F: soil fertility class (1 = low; 2 = moderate; 3 = high), IN1 andIN2: mineral fertilizer and manure applied (kg ha − 1 yr − 1 ) respectively, TNU and TKU: total N and K uptake (kg ha − 1 yr − 1 ), respectively. Nitrogen lost from agricultural soils in the form of denitrification and volatilization is considered as gaseous loss (OUT4) (Stoorvogel and Smaling, 1990 ). Similar with leaching, direct measurement of N loss in gaseous form is difficult thus it was estimated by regression equation (Aticho et al., 2011 ). OUT4 = (0.025 + 0.000855 \(\times\) P+0.01725 \(\times\) IN1 + IN2 + 0.117) + (0.113 \(\times\) IN1 + IN2) (14) Where, P = mean annual rainfall; IN1 + IN2: mineral fertilizer and manure applied (kg ha − 1 yr − 1 ), respectively. Nutrient outflow due to soil erosion (OUT5) was directly measured. First the total runoff coming out of the catchments estimated using a 90 o v-notch weir. Continuous sediment samples were done over the rainy season. The nutrients lost as suspension and sediment fixed were calculated in the lab. Total amount of nutrient lost with erosion were then quantified by the sum of nutrient losses which is dissolved with the runoff water after the sediment is filtered and nutrient loss along with the sediment. The amount of discharge for general sharp crested triangular weir with angle θ is calculated as described below (Piratheep et al ., 2006). $$Q=\frac{8}{15}\sqrt{2g}{C}_{d}{\text{tan}}^{\left(\raisebox{1ex}{$\theta $}\!\left/ \!\raisebox{-1ex}{$2$}\right.\right)}{h}_{e}^{\left(\raisebox{1ex}{$5$}\!\left/ \!\raisebox{-1ex}{$2$}\right.\right)}$$ 15 $${h}_{e}={h}_{U}+{k}_{h}$$ 16 Where: Q (m³/s) is flow over v-notch weir 𝐶 d is discharge coefficient K h is correction factor for the head h e is effective head of the weir h 𝑢 (m) is the head flowing through the notch θ (degrees) is the notch angle g is the acceleration of gravity (9.81 m/s²) This equation has been simplified for a 90 o sharp crested v-notch (Rantz, 1982), and was used in this study using Eq. 17. Q = 2.49h e 2.48 (17) 2.8 Laboratory analysis 2.8.1 Runoff water sample collection and analysis Runoff stage was recorded every five minutes from the outlets of each land use/land cover class during rain events, which were later composited on a monthly basis. After collection, runoff samples were filtered and air dried. The sediment were filtered by Whatman filter paper, air-dried, sieved by 2 mm sieve and analyzed by following standard laboratory procedures while, the nutrient in the water was thoroughly mixed and re-sampled for the nutrient analysis from solution. The NPK contents of both plants and soil were analyzed in Amhara Design and Construction Enterprise laboratory. 2.8.2 Plant sampling and analysis To determine OUT1 and OUT2, a 1 m 2 quadrant were used for sampling teff, wheat and litter fall. Fresh crop biomass was weighed immediately after harvest using field balance, crop grain was collected and weight of grain and straw was measured separately, and then both straw and grain were taken for laboratory analysis. The plant material was prepared through drying at a maximum of 60 to 70°C, grinded to pass through a 0.15 mm mesh (Anderson & Ingram, 1993). Total nitrogen was determined by Kjeldahl method (Kirk, P.L.1950) Phosphorus was determined colorimetrically by using molybdate and metavandate for color development (van Reeuwisk, L. 1992). Potassium (K) was determined by flame photometer (Morgan, 1941 ). Soil nutrient contents were also determined using standard method; available P was extracted by Olsen method (Olsen and Dean, 1965 ), and P was then determined using spectrophotometer;total nitrogen was determined by Kjeldahl method and available potassium (K) was extracted by Morgan’s solution and K in the dissolved solution was measured by flame photometer. To determine the amount of nutrient input in the form of animal manure on the grazing land, the amount of available manure were derived from the number of livestock within the study area, using excretion, nutrient content and loss factors. The amount of manure sample needed to analyze each nutrient in the laboratory was similar as described above. Nutrients in manure as excreted for all livestock were estimated by multiplying the quantity of manure excreted (wet weight) times the nutrient content of manure excreted. But, N loss directly from livestock (e.g. ammonia volatilization from stored manure) is not included in the balance, although livestock manure production is a major source of N input. Livestock manure N production: total numbers of live animals multiplied by respective coefficients of the quantity of N contained in manure per animal per year. Composite samples of fresh manure from the grazing land were collected and analyzed for composition of N and P in laboratory. The manure samples were oven dried at 105°C before analysis (Saleem, 1998 ). 2.8.3 Nutrient balance analysis Nitrogen, phosphorus and potassium (kg ha − 1 yr − 1 ) balance were obtained by subtracting the quantity of NPK removed from soil through crop products (OUT1), crop residues (OUT2), leaching (OUT3), gaseous lose (OUT4) and erosion (OUT5) from the total amount of N, P and K added to the system with mineral fertilizer (IN1), manures (IN2), biological nitrogen fixation (IN3), and wet deposition (IN4) (Smaling et al., 1998 ). 3. RESULTS AND DISCUSSION 3.1 Nutrient Inflow in to the Catchments According to the information obtained through discussion with farmers, the only fertilizers applied by the farmers in the study area were urea and NPS. The fertilizer rate used by the farmers was known by interviewing the teff and wheat producing farmers found in the area. The amount of fertilizer used by the farmer in the study area was 120 kg ha − 1 NPS for teff ( Eragrostis tef ) cropland and 100 kg ha − 1 NPS and 60 kg ha − 1 urea for wheat cropland. The use of fertilizer in the study area was better compared to the national average rate of 43 kg urea ha − 1 and 65 kg DAP ha − 1 (Elias et al., 2019 ). Except their farm yard plot, farmers in the study area did not apply animal manure and compost to their main arable land. This could be influenced by their settlement location which creates inconveniencies to prepare and transport manure, use of dung for household energy, and its small quantity which is only enough to their backyard lands. Nutrient input and output of each land use and land cover (LULC) is different. For instance, in farming system crop product (OUTPUT1) and residue (OUTPUT 2) were taken in to account as a special nutrient output from the other LULC. Similarly, plant litter fall and animal manure are type of nutrient inputs for the natural forest and grazing land respectively. Unlike the other land use system, inorganic fertilizers were the major nutrient input for cultivated land in the study area. Table 2 Nutrient inflow (TNIN) on Teff and Wheat cropland Cropping Land Mineral Fertilizer Organic Fertilizer Wet Deposition Nitrogen Fixation Total Nutrient Input N P N P K N P K N N P K Teff 22.7 19.8 0 0 0 5 0.8 3.3 4 31.7 20.6 3.3 Wheat 50.2 16.5 0 0 0 5 0.8 3.3 4 59.2 17.3 3.3 The nutrient inputs from NPS fertilizer for teff ( Eragrostis tef ) cropland were estimated at 22.7 kg N ha − 1 yr − 1 and 19.8 kg P ha − 1 yr − 1 . While the nutrient inputs added to wheat cropland was estimated 50.3 kg N ha − 1 yr − 1 and 16.5 kg P ha − 1 yr − 1 . Wet deposition (IN3) and nitrogen fixation (IN4) were the other nutrient inputs considered in this study. In reality, teff and wheat are not leguminous crops but all crops benefit from N that is settled non-symbiotically which performed by blue green algae and free-living bacteria, most particularly (Azotobacter, Beijerinckia and Clostridium) or by N-fixing trees that are cleared out on the field (Rhizobia and Actinomycetes spp.) (Aticho et al., 2011 ). The value of nitrogen added to the farm through wet deposition (IN3) and nitrogen fixation (IN4) for both croplands were estimated to be 5 kg ha − 1 yr − 1 and 4 kg ha − 1 yr − 1 respectively. However, the P and K inputs due to wet deposition were only 0.8 kg ha − 1 yr − 1 and 3.3 kg ha − 1 yr − 1 obtained from the pedo transfer function (Table 2 ). The nutrient inputs from NPS fertilizer in the present study was very high compared to the national level (Haileslassie et al. 2005 ) which was estimated to be 12.24 kg N ha − 1 yr − 1 and 12.87 kg P ha − 1 yr − 1 . The sequence of total N, P and K inputs (TNIN, TPIN, TKIN) for teff ( Eragrostis tef ) crop land from all sources (inorganic fertilizer, wet deposition and nitrogen fixation) was 31.7 kg ha − 1 yr − 1 , 20.6 kg ha − 1 yr − 1 , 3.3 kg ha − 1 yr − 1 and for wheat cropland it was 59.2 kg ha − 1 yr − 1 , 17.3 kg ha − 1 yr − 1 and 3.3 kg ha − 1 yr − 1 ( Table 3 ). Hence, the phosphorus inputs were higher for teff ( Eragrostis tef ) while nitrogen was higher for wheat cropland. Because, this high amount of nitrogen for wheat crop was mainly due to the application of NPS. However, the high amount of P content which was estimated in teff ( Eragrostis tef ) cropland might be due to the use of higher level of P (38%) in 100 kg of NPS during sowing time. NPS fertilizer also contains 7% of sulfur from the total proportion but in the present study we did not analyze sulfur rather we focused on only the three primary nutrients (N, P and K). These values were obtained from the standardized proportion of NPS which had the consecutive rate of 19:38:7. The potassium level added to the system was no not analyzed as potassium is not scarce in the Ethiopian soils. Due to this reason the common source of K nutrient input for each land use was wet deposition obtained by pedo transfer function (Equ. 7). But, livestock manure for grazing land and leaf litter fall for forest land also contributed some amount of potassium. Table 3 Nutrient input into different land use land cover type (kg ha -1 yr -1 ) Land Use Land Cover Type Mineral Fertilizer Organic fertilizer Wet Deposition Nitrogen fixation N P K N P K N P K N Natural Forest 0 0 0 15.3 2.3 0.24 5 0.8 3.3 4 Grazing land 0 0 0 4.4 0.1 6.01 5 0.8 3.3 4 Bare land 0 0 0 0 0 0 5 0.8 3.3 0 Rehabilitatedland 0 0 0 0 0 0 5 0.8 3.3 4 As described in the above paragraph, in addition to biological nitrogen fixation and wet deposition, plant litter fall were considered for natural forest instead of organic fertilizer for cultivated land which is used as INPUT2. As observed in Table 3 , Litterfall is the dominant pathway for nutrient return to the soil, especially for nitrogen (N) and phosphorus (P).However, in bad land area no plant species was provided and the nitrogen input through symbiotic fixation was nil. To estimate the amount of nutrient input to the grazing land, the number of livestock, the length of time keeping on that controlled grazing land and the average amount of dung/muck per day to estimate the N, P and K nutrient content of animal manure were asked from the local farmers. On average three livestock were kept in the study grazing plot area. The cattle spent ten hours in the field per day and a single cow drops its defecations three times a day equivalent to 1.2 kg as fresh animal dung and 0.3 kg dry matter dung as estimated in the study plot. Animals may graze outside these two catchments in dry season after the crop is harvested. However, in cropping (summer) season, they are kept in the specified catchment. In dry season people also collect their domestic fuel wood outside these two catchments and housewives use part of the animal droppings for domestic energy purposes. Actually, the loss of animal dropping in these multiple ways make a fallacy on annual nutrient balance in grazing land. Nevertheless, to recover this misleading value of nutrient balance, we used 15% removal factor during nutrient (N, P and K) quantification (Saleem, 1998 ). Forests receive a high amount of nutrient inputs from plant litter fall which was taken into account as INPUT2 and amount of N, P and K estimated from plant litter fall was 15.3 kg ha − 1 yr − 1 , 2.3 kg ha − 1 yr − 1 and 0.24 kg ha − 1 yr − 1 respectively. Atmospheric deposition and nitrogen fixation were the other major nutrient input mechanisms into the land use system. The value estimated from atmospheric deposition was 5 kg N ha − 1 yr − 1 , 0.8 kg P ha − 1 yr − 1 , 3.3 kg K ha − 1 yr − 1 and 4 kg N ha − 1 yr − 1 via nitrogen fixation (Table 3 ). The results of N, P and K INPUT estimated from wet deposition and nitrogen fixation in this study were comparable to similar other studies (Haileslassie et al., 2005 ). 3.2 Nutrient Outflow from the Catchment From the cultivated land, the main nutrient outflows were in the form of crop harvested product and crop residue/straw. In this study, it was estimated 17.2 kg N ha − 1 yr − 1 , 2.8 kg P ha − 1 yr − 1 , 0.16 kg K ha − 1 yr − 1 losses in harvested product (OUT1) for teff ( Eragrostis tef ) and 17 kg N ha − 1 yr − 1 , 9.5 kg P ha − 1 yr − 1 , and 0.17 kg K ha − 1 yr − 1 for wheat cropland. Whereas, the losses of N, P and K via crop residues (OUT2) were 22.8 kg ha − 1 yr − 1 , 6 kg ha − 1 yr − 1 , 0.9 kg ha − 1 yr − 1 for teff and 11.9 kg ha − 1 yr − 1 , 8.01 kg ha − 1 yr − 1 , 0.4 kg ha − 1 yr − 1 for wheat cropland respectively (Table 4 ). In the present study, the loss of potassium level from crop product and crop residue was very low compared to the study by Haileslassie et al. ( 2005 ). The higher depletion of K in the preceding one could be associated with continuous cultivation, total evacuation of crop residues from farmlands, absence of crop rotation, unequal fertilizer application, soil disintegration, misfortune of organic matter (OM) and insufficient fertilizer application (Laekemariam et al. , 2018). Kiros et al. ( 2014 ) also reported the losses of N, P and K via harvested crops (OUT1) at the catchment level were varied from 28.69–82.64 kg ha − 1 yr − 1 , 0.12–0.32 kg ha − 1 yr − 1 and 9.37–18.02 kg ha − 1 yr − 1 respectively across the different landscapes and socio-economic groups respectively. However, the three macro-nutrient losses through crop yield in the present study were very low compared to other studies (Kiros et al. ( 2014 ). In the previous studies, nutrient outflow quantification was undertaken in more cereal crops including teff and wheat and in different landscapes. Agroecology, soil type, amount of nutrient input or fertilizer application rates, area coverage, precipitation and amount of runoff also can be the other factor to contradict the nutrient loss from similar land use between the current study and similar other studies. Table 4 Nutrient output from each land use land cover type (kg ha -1 yr -1 ) Land Use/Land Cover Type Crop yield Crop residue Leaching Gaseous loss Soil erosion N P K N P K N K N N P K wheat cropland 17 9.5 0.17 11.9 8.01 0.4 15.6 26 7.6 28 0.5 14.6 Teff cropland 17.2 2.8 0.16 22.8 6 0.9 10.1 14.5 4 39 0.7 14.4 Rehabilitated land 0 0 0 0 0 0 5.8 5.5 1.2 36.1 1.07 5.3 Badland 0 0 0 0 0 0 5.8 5.5 1.2 50.6 1.18 18.3 Grazing land 0 0 0 0 0 0 9.7 7.5 10 43.8 0.55 4.9 Natural Forest 0 0 0 0 0 0 19.5 6.8 31.8 11.38 0.31 2.9 Table 4 shows that the major nutrient outputs from cultivated land were crop yield (OUT1), crop residue (OUT2), and erosion (OUT5). Higher N, P, K losses having the corresponding value (22.8 kg ha − 1 yr − 1 , 6 kg ha − 1 yr − 1 , 0.9 kg ha − 1 yr − 1 ) were observed in crop residue than in crop yield ( 17.2 kg ha − 1 yr − 1 , 2.8 kg ha − 1 yr − 1 , 0.16 kg ha − 1 yr − 1 ) in teff cropland as a result of higher biomass of crop residue (straw)ha − 1 obtained compared to its grain product. The estimated value of N, P, K losses through crop residue in this study differ from the findings by Kiros et al. ( 2014 ). But for the other fields leaching (OUT3), gaseous losses (OUT4) including erosion (OUT5) were identified as a common nutrient output from the system. Among the different land use/land covers, higher nutrient lose by erosion (OUT5) was recorded due to the presence of higher erosion from the area. Comparably, higher N nutrient losses had been estimated in soil erosion than the other output pathways (Table 4 ). In general, nitrogen and potassium loss through erosion were higher as compared to phosphorus, as N and K are mobile nutrients and easily transferred through erosion (Bekunda et al., 2002 ). As observed in Table 4 , however, phosphorus is an immobile nutrient although some amount is generally transferred to water through sediment-based runoff or erosion. Similarly, phosphorus depletion is negligible in leaching compared to N and K. Leaching losses of N and K in wheat were higher than teff crop land. Unlikely, leaching losses were lower in rehabilitated land and bad land compared to all land use/land covers (Table 4 ). This inconsistency may be due to the low amount of soil water nutrient concentration, soil physical characteristics, climate, rainfall intensity, low soil moisture, and poor water retention capacity of soils. N losses via denitrification (OUT4) from cereal crops (7.6 kg ha − 1 yr − 1 in wheat and 4 kg ha − 1 yr − 1 in teff crop land)were comparable to the finding by Haileslassie et al., ( 2005 ) (5.6 kg ha − 1 yr − 1 ). This can be the use of the same way of estimation, presence of similar amount of annual precipitation and amount of input and output value contributed in the equation. Because average annual precipitation, nutrient input and outputs are the major components used during nitrogen loss estimation through denitrification (Eq. 11). 3.3 Nutrient Balances on different land use/land covers 3.3.1 Partial nutrient balance on cultivated land Partial nutrient balances estimated for agricultural lands are basically anthropogenic balances, and do not take into account natural mechanisms like wet deposition, nitrogen fixation, leaching, and gaseous loss. The partial nutrient balances (aggregated by teff and wheat cropland), which is the difference between sum of outputs (OUT1 + OUT2) and sum of inputs (IN1 + IN2) (Haileslassie et al., 2006 ). However, in this study the value of N, P and K nutrient from organic fertilizer (IN2) were zero because the farmers did not apply animal manure or compost in their farmland. Table 5 Partial nutrient balances for teff and wheat cropland (kg ha -1 yr -1 ) Land Use IN1 + IN2 OUT1 + OUT2 Partial Balance N P K N P K N P K Teff 22.7 19.8 0 40 8.8 1.06 -17.3 11 -1.06 Wheat 50.2 16.5 0 28.9 17.5 0.57 21.3 -1 -0.57 The consequence of the partial nutrient balance proved that the nutrient removals by the crop harvest and crop residues were the most contributors to the N and K negative partial balances in both croplands. The N, P and K partial balances for teff cropland were estimated − 17.3 kg ha − 1 yr − 1 , + 11 kg ha − 1 yr − 1 , -1.06 kg ha − 1 yr − 1 respectively. However, for wheat cropland + 21.3 kg N ha − 1 yr − 1 , -1 kg P ha − 1 yr − 1 , -0.57 kg K ha − 1 yr − 1 were estimated (Table 5 ). Even if the partial nitrogen for teff and phosphorus nutrient balance indicated positive in wheat crop production system, the value implied was at warning to become negative balance for the future unless the nutrient management is improved. The partial balance of potassium content observed in this study is slightly negative in both croplands. This does not imply that potassium mining from the area is low as this only shows the partial nutrient balance of a wheat farm. The same is true that, positive N partial balance for wheat and P for teff cropping land is not the indication for nutrient accumulation in the area. Based on the partial input-output nutrient balance, the study area shows phosphorus had positive partial balances for both croplands. Wheat farming system had positive nitrogen partial balances and negative for teff. Unlike N and K, a positive balance of P was observed in both agricultural lands. Except the nitrogen balance for wheat which was positive, this study is in line with the finding of other studies (Haileslassie et al., 2006 ; Kiros et al., 2014 ). Therefore, net negative soil nitrogen balances in teff cropland represent a significant concern to the long-term sustainability of soil resource in a broad context that extends beyond soil nutrient availability (Table 5 ). 3.3.2 Full nutrient balances Unlike the partial nutrient balance which was calculated by considering only anthropogenic ways of nutrient input and output, the full nutrient balance were quantified by using both anthropogenic and natural mechanisms like wet deposition, nitrogen fixation, leaching, and gaseous loss of nutrient import and export. Therefore, the full nutrient balances were estimated by considering the difference between total nutrient output from the total nutrient input (total nutrient input-total nutrient output) (Stoorvogel and Smaling, 1998). Table 6 Total nutrient inputs and outputs (kg ha − 1 yr − 1 ) for different land use/land cover type LULC Total Nutrient input Total Nutrient Output TNIN TPIN TKIN TNOUT TPOUT TKOUT Teff Crop land 31.7 20.6 3.3 93.1 9.5 30 Wheat Crop land 59.2 17.3 3.3 80.1 18.01 41.17 Natural Forest 24.34 3.1 3.5 62.7 0.31 9.7 Grazing land 13.4 1 9.3 63.5 0.55 12.4 Bad land 9 0.8 3.3 57.6 1.18 23.8 Rehabilitatedland 9 0.8 3.3 43 1.07 10.8 Hint: TNIN = total nitrogen input, TPIN = total phosphorus input, TKIN = total potassium input Table 6 summarizes the total nutrient inputs and outputs for the major crops (teff, wheat) and other land use/land covers found in the study sub-catchments. As compared to the other nutrients, N balances indicated higher negative value for each land use/land cover. Because, nitrogen is very susceptible to loose in all output mechanisms. The full nutrient balance results were different across the six land use/land covers. In this study, negative nitrogen and potassium balances were observed in all land use and land covers. The full balances for the major cropland mainly wheat and teff were estimated to be -20.9 kg N ha − 1 yr − 1 , -0.7 kg P ha − 1 yr − 1 , -37.87 kg K ha − 1 yr − 1 for wheat and − 61.4 kg N ha − 1 yr − 1 , + 11 kg P ha − 1 yr − 1 , and − 26.7 kg K ha − 1 yr − 1 for teff cropland (Fig. 2 ). As observed in Fig. 2 , higher negative balances were found in teff cropping land and badland. Because higher nutrients especially nitrogen were lost from these two land use/land cover through erosion (Table 6 ). In wheat cropland, rehabilitated and badland, the phosphorus balances indicated slightly negative (-0.7, -0.27 kg ha − 1 yr − 1 , and − 0.38 kg ha − 1 yr − 1 correspondingly) whereas the other LULC had positive P balances (Fig. 2 ). The possible reason to become negative nutrient balance in natural forest may be the increasing of biomass demand, animal disturbance, and higher infiltration leads to higher nutrient removal through leaching. And these problems can be avoided by decreasing biomass harvest intensities, recycling harvest leftovers and area closure. 3.4 Discussion The partial balances of N, P and K in this finding is in agreement with the study by Haileslassie et al. ( 2006 ) for teff cropland but it differs for wheat cropland which was estimated − 9 kg N ha − 1 yr − 1 , 8 kg P ha − 1 yr − 1 , -11 kg K ha − 1 yr − 1 and − 21 kg N ha − 1 yr − 1 , 0 kg P ha − 1 yr − 1 , -21 kg K ha − 1 yr − 1 for the corresponding nutrient type and cropping land by the previous one. The reason for the variation of partial nutrient balance in wheat cropland may be due to differences in the amount and type of fertilizer application, soil and water conservation, and nutrient management practices. Except for P, the partial N and K balances in this study are in agreement with other studies for teff while it differs for wheat crop land (Haileslassie et al. , 2007) who reported − 50 kg N ha − 1 yr − 1 ,-8 kg P ha − 1 yr − 1 , -41 kg K ha − 1 yr − 1 (for wheat) and − 8 kg N ha − 1 yr − 1 , + 10 kg P ha − 1 yr − 1 , -16 kg K ha − 1 yr − 1 for teff crop land. However, this study contradict with the study by Haileslassie et al. ( 2005 ) who reported positive partial nutrient balances for the Tigray Region (+ 10 N, + 6 P, + 10 K kg ha − 1 yr − 1 ) and for Ethiopia (+ 10 N, + 11 P, + 7 K kg ha − 1 yr − 1 ) at national level. The current study shows a lower estimate compared to the national level. The lower estimates reported in this study might be due to the lack of organic fertilizer application. The results of the partial nutrient balance showed that the nutrient removals by the crop harvest and crop residues were the greatest contributors to the N and K negative balances in teff cropland. Positive nitrogen partial balance in wheat cropland and positive phosphorus partial balance in both croplands were observed in this study. The negative N partial balance in teff cropland may be associated with the removal of higher biomass of crop residue from the area. The level of potassium in the balance was negative for both crops. This may be due to the absence of potassium fertilizer and other K inputs to the farm. The only source of potassium in the farm was through wet deposition (IN3) which was estimated using transfer function. 3.5 SUMMARY, CONCLUSION AND RECOMMENDATION Nutrient inputs, outputs and nutrient balances from this study show that soil nutrient depletion is a major problem in the study area. Particularly N and K showed negative balances in all the land uses primarily due to large removals of nutrients by erosion, harvested output, crop residue, leaching and gaseous loss due to poor nutrient management. The findings also showed that nutrient depletions were more severe in the crop lands than the other land uses. Nutrient losses through crop harvest (grain and straw) contribute the most important sources of nutrient mining. Nutrient losses along with soil erosion by water were identified the dominant factor for nutrient depletion in all land uses which was measured based on nutrient content in the eroded sediments and as dissolved nutrients in the runoff water. Especially nitrogen loss was higher through erosion which could be caused by the mobile nitrate. It was distinguished that nutrient losses were much higher in the runoff water (dissolved) compared to the sediment bounded nutrients. There was seasonal variation in the quantities of nutrient export through soil erosion from each land use/land cover. The partial nutrient balances for teff cropland were strongly negative than wheat. Because without the potassium balance indicated slightly negative, N and P had positive partial balances for wheat crop land. N and K had negative nitrogen full balance for both cropping system whereas with the exception of rehabilitated and bare land, phosphorus had positive balance. Unlike partial balances for wheat cropland which had positive nitrogen balance, full balances were negatives compared to partial nutrient balances, full nutrient balances had negative nitrogen and potassium value for all land use/land cover because nutrients in the full balance were lost largely through leaching, denitrification, runoff and sediment transport. Consequently, the study area needs improvements in nutrient use efficiency from different inputs, awareness creation through integrated nutrient management to mitigate nutrient removal and there by improve the sustainability and productivity of the system. The information on flow of nutrients and their balance in different land use can be used for future management of the systems for their sustainable production. In general, the negative partial and full balances observed in cultivated land and other land uses were used as indicators for improvements in soil fertility management. Further nutrient balance analysis studies should be promoted at different spatial scale to identify the level of nutrients in the soil and to determine proper nutrient management practice and to recommend appropriate rates and types of fertilizer application with a little impact on the environment or water quality of water bodies. The study also identified that nutrients are transported to the atmosphere, ground water and to the surface water. Thus, proper nutrient application methods and land use management should be further studied to reduce the risk of nutrient transport to surface and ground water, or into the atmosphere. Declarations Data Availability The data used to support the findings of this study are available from the corresponding author upon request. Conflict of Interest The authors declare that they have no conflicts of interest. Funding The authors would like to thank Bahir Dar University Institutional University Cooperation (BDU-IUC) Programme and Debre Markos University for providing financial support for the data collection and for the write up of the result of this manuscript. Acknowledgement The Bahir Dar University Institutional University Cooperation (BDU-IUC) Programme and Debre Markos University is gratefully acknowledged for supporting this research. References Aremu, M. O., Olaofe, O., & Akintayo, E. T. (2006). Chemical composition and physicochemical characteristics of two varieties of bambara groundnut (Vigna subterrenea) flours. J. Appl. Sci , 6 (9), 1900-1903. Aticho, A., Elias, E., & Diels, J. (2011). Comparative analysis of soil nutrient balance at farm level: a case study in Jimma Zone , Ethiopia. International Journal of Soil Science , 6 (4), 259-266. Bekunda, M., Nkonya, E., Mugendi, D., & Msaky, J. 2002. Soil fertility status, management, and research in East Africa. East African Journal of Rural Development, 20 (1), 94-112. Brady, N. C., & Weil, R. R. 2008. The nature and properties of soils (Vol. 360): Pearson Prentice Hall Upper Saddle River. De Jager, A. 2005. Participatory technology, policy and institutional development to address soil fertility degradation in Africa. Land Use Policy, 22 (1), 57-66. Elias, E., Okoth, P. F., &Smaling, E. M. A. (2019). Explaining bread wheat (Triticum aestivum) yield differences by soil properties and fertilizer rates in the highlands of Ethiopia. Geoderma , 339 , 126-133. Gashaw, T., Bantider, A., &Mahari, A. (2014). Evaluations of land use/land cover changes and land degradation in Dera District, Ethiopia: GIS and remote sensing based analysis. International Journal of Scientific Research in Environmental Sciences , 2 (6), 199. Haileslassie, A., Priess, J. A., Veldkamp, E., &Lesschen, J. P. (2006). Smallholders’ soil fertility management in the Central Highlands of Ethiopia: implications for nutrient stocks, balances and sustainability of agroecosystems. Nutrient Cycling in Agroecosystems , 75 (1-3), 135-146. Haileslassie, A., Priess, J., Veldkamp, E., Teketay, D., &Lesschen, J. P. (2005). Assessment of soil nutrient depletion and its spatial variability on smallholders’ mixed farming systems in Ethiopia using partial versus full nutrient balances. Agriculture, ecosystems & environment , 108 (1), 1-16. Kirk, P. L. 1950. Kjeldahl method for total nitrogen. Analytical Chemistry, 22 (2), 354-358. Kiros, G., Haile, M., & Gebresamuel, G. (2014). Assessing the input and output flows and nutrients balance analysis at catchment level in Northern Ethiopia. Journal of soil science and environment management , 5 (1), 1-12. Lesschen, J., Stoorvogel, J., Smaling, E., Heuvelink, G., &Veldkamp, A. 2007. A spatially explicit methodology to quantify soil nutrient balances and their uncertainties at the national level. Nutrient Cycling in Agroecosystems, 78 (2), 111-131. Morgan, M. F. 1941. Chemical diagnosis by the Universal Soil Testing system. Agr.Exp.Sta. (New Haven) Bull.450 . Olsen, S., & Dean, L. 1965. Phosphorus. Chemical and microbiological properties. Methods of Soil Analysis, Part, 2 , 1035-1048. Saleem, M. M. 1998. Nutrient balance patterns in African livestock systems. Agriculture, Ecosystems & Environment, 71 (1-3), 241-254. Smaling, E. M., Lynam, J., & Nandwa, S. 1998. Nutrient balances as indicators of productivity and substainability in Sub-Saharan African agriculture: Papers Presented during the conference Soil Fertility Management in Sub-Saharan Africa" held in Nairobi, February 1997. Agriculture, ecosystems and environment, 71 (1/3). Smaling, E., Stoorvogel, J., &Windmeijer, P. 1993. Calculating soil nutrient balances in Africa at different scales. Fertilizer research, 35 (3), 237-250. Stoorvogel, J. J., & Smaling, E. M. A. 1990. Assessment of soil nutrient depletion in Sub-Saharan Africa: 1983-2000. Vol. 2: Nutrient balances per crop and per land use systems (0924-3062). Van Beek, C. L., Elias, E., Yihenew, G. S., Heesmans, H., Tsegaye, A., Feyisa, H., ... &Mengist, S. (2016). Soil nutrient balances under diverse agro-ecological settings in Ethiopia. NutrientCycling in Agroecosystems , 106 (3), 257-274. Van Beek, C., Brouwer, L., & Oenema, O. 2003. The use of farm gate balances and soil surface balances as estimator for nitrogen leaching to surface water. NutrientCycling in Agroecosystems, 67 (3), 233-244. Van Reeuwijk, L. 1992. Procedures for soil analysis. ISRIC, Wageningen, the Netherlands. Procedures for soil analysis. 3rd ed. ISRIC, Wageningen, the Netherlands . Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3893338","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":269250781,"identity":"8b19fe32-7aba-4b81-8920-bae8ba8feb02","order_by":0,"name":"Melese Gezie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+0lEQVRIiWNgGAWjYFAC5gYozcD44EMFiAETwQkY4VqYDWecATFgIgS1MDCwSXO2oYpgBbrtjY0Pf1TUysm3Mx+QZpxXG83fDtTyo2IbTi1mZw42G/OcOW7M2MyWYFy47XjujMOMDYw9Z27j1nIjsU2ase1YYjMzj0HyzG3HchuAWpgZ2/Bouf+w/efPf8fq25j5PxzmnXMsdz5BLTcY2xh4G2oSeJh5GJuBjNwNBLWcSWyW5jl2wHAGM5sx44xjB3I3ArUcxOuX44cPfvxRUycv33/4+Y8PNXW5884fPvjgRwVuLVBwGJVxgJB6IKjDYIyCUTAKRsEogAMAOvxgBbnntRgAAAAASUVORK5CYII=","orcid":"","institution":"Debre Markos University Burie Campus","correspondingAuthor":true,"prefix":"","firstName":"Melese","middleName":"","lastName":"Gezie","suffix":""},{"id":269250782,"identity":"b10be948-8b0d-4261-816d-e64fb9d4b8cd","order_by":1,"name":"Enyew Adgo","email":"","orcid":"","institution":"Bahir Dar University","correspondingAuthor":false,"prefix":"","firstName":"Enyew","middleName":"","lastName":"Adgo","suffix":""},{"id":269250783,"identity":"3a9d6b63-eccd-44d2-a0ea-47504a001b61","order_by":2,"name":"Habtamu Assaye","email":"","orcid":"","institution":"Bahir Dar University","correspondingAuthor":false,"prefix":"","firstName":"Habtamu","middleName":"","lastName":"Assaye","suffix":""},{"id":269250784,"identity":"2038f86e-27c8-4c27-a92d-095dbbbac4bf","order_by":3,"name":"Alemayehu Wassie","email":"","orcid":"","institution":"Bahir Dar University","correspondingAuthor":false,"prefix":"","firstName":"Alemayehu","middleName":"","lastName":"Wassie","suffix":""}],"badges":[],"createdAt":"2024-01-24 07:44:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3893338/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3893338/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":50367792,"identity":"6a5dc1db-549a-441a-97cf-efca5786efcd","added_by":"auto","created_at":"2024-01-30 12:16:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":202086,"visible":true,"origin":"","legend":"\u003cp\u003eMap of the study area\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3893338/v1/7690df753e1b8c040f3856d2.png"},{"id":50367807,"identity":"3e41138b-dd72-43d8-be93-9f0149f5f508","added_by":"auto","created_at":"2024-01-30 12:16:17","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":23236,"visible":true,"origin":"","legend":"\u003cp\u003eN, P and K full balances of each land use/land cover type\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3893338/v1/420dea5bbb1b57f5b91224d7.png"},{"id":50414302,"identity":"32204e15-982b-4ea1-9950-b4dbccfd3560","added_by":"auto","created_at":"2024-01-31 07:52:31","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":696581,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3893338/v1/6ac976b0-6585-407f-9139-fe318c1177b6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eNutrient Balance in Small Catchments of the Upland Areas of the Gumara River, Northwestern Ethiopia\u003c/p\u003e","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eSoil fertility decline is one of the main constraints of agricultural productivity in Africa. Soil nutrient balance studies in Africa show evidence of widespread nutrient mining leading to severe nutrient deficiencies. Negative nutrient balances of \u003cb\u003eN\u003c/b\u003e and \u003cb\u003eP\u003c/b\u003e are reported throughout the smallholder farming systems of Africa (Stoorvogel and Smaling, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e1990\u003c/span\u003e). Soil degradation in the form of nutrient depletion, is a major factor for the declining of agricultural production in Ethiopia (Wassie Haile \u003cem\u003eet al.\u003c/em\u003e, 2009). According to Gebremedhin Kiros et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), many nutrient balance studies in Ethiopia reported negative value. In many studies, partial nutrient balance at land use level are negative for the teff based farming system in the central high lands of Ethiopia. The study conducted by Van Beek et al. (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). National averages of nutrient balances were estimated at -41 kg N, -6 kg P and \u0026minus;\u0026thinsp;26 kg K ha-\u003csup\u003e1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which is among the highest nutrient depletion rates for sub-Saharan Africa. Soil nutrient degradation has become a major agricultural problem in central highlands of Ethiopia. It realized that food security cannot be achieved in the region without overcoming the problem of nutrient depletion. There are a number of studies which revealed that lack of plant nutrient is one of the main causes for low agricultural production and food security in Africa \u003cb\u003e(\u003c/b\u003eAmare Haileslassie et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn the past, measurement of nutrient balances were addressed at sub-continental and national scales without addressing the large spatial variability of nutrient balances within a region and catchment level (Amare Haileslassie et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Low productivity caused by soil degradation also the major problem in the study area. These factors minimize the adaptive capacity and exacerbate the vulnerability of farmers to future changes, such as: climate change and hydrological processes in the Lake Tana basin. Due to these multiple problems, it is very important to analyze the balance and monitor nutrient flows in and out from the farmlands and from the different land use type in the particular micro-catcment.\u003c/p\u003e"},{"header":"2. MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1 Description of the Study Area\u003c/h2\u003e\n \u003cp\u003eThe study was carried out in upper reaches of Lake Tana basin of Areb Gebeya area in northwestern Ethiopian. Specifically, the study sub-watersheds are found in Gumara watershed which is one of the major watersheds of Lake Tana basin. \u003cem\u003eGumara\u003c/em\u003e watershed is found in the eastern part of the Lake Tana basin. The watershed at the lake inlet is 1970 km\u003csup\u003e2\u003c/sup\u003e and 65% of it is gauged. It originates at the foot of Mount \u003cem\u003eGuna\u003c/em\u003e which has an elevation of 4120m.a.s.l (Gashaw et al., \u003cspan class=\"CitationRef\"\u003e2014\u003c/span\u003e). Geographically, the particular study area, \u003cem\u003eEnkulal\u003c/em\u003e watershed is located between 11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;57\u0026rdquo;-11\u003csup\u003eo\u003c/sup\u003e88\u0026rsquo;9\u0026rdquo; latitude and 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;37\u0026rdquo;-37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;13\u0026rdquo; longitude (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). The area was selected by Land Resilience Research Team of the Bair Dar University- Institutional University Cooperation Programme(BDU-IUC) for the analysis of nutrient balance research. Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e below is showed the general overview of the location of the study area and site characteristics.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eStudy area sampling locations and site characteristics\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLand use land cover type\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eArea of sample plot (ha)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eLatitude\u0026nbsp;(N)\u0026nbsp;and Longitude(E)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAltitude (m)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCultivated land(wheat)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;14\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;31\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2497\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCultivated land(teff)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e38\u0026rsquo;13\u0026rsquo;\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;32\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2419\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNatural forest\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;21\u0026rsquo;\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;31\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2476\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRehabilitated land\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;49\u0026rsquo;\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;57\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2487\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBad land\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;57\u0026rsquo;\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;37\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2480\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGrazing land\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003csup\u003eo\u003c/sup\u003e37\u0026rsquo;59\u0026rsquo;\u0026rsquo; \u003cspan\u003e$\u003c/span\u003e 37\u003csup\u003eo\u003c/sup\u003e48\u0026rsquo;22\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e2431\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2 Climate, Agroecology, Geology and soil of the study area\u003c/h2\u003e\n \u003cp\u003eAgro-climatic conditions of the study area is tepid moist mid highlands. The maximum and minimum temperature of the study area is 25\u003csup\u003eo\u003c/sup\u003ec and 18 \u003csup\u003eo\u003c/sup\u003ec respectively, and the average annual rainfall is 1250 mm. The altitude range of the kebele is 2200 to 2600 m.a.s.l. Sixty nine percent of the watershed has slopes of more than 8% and 96% is crop land. The main soil types of the study area particularly in the upland areas of the \u003cem\u003eGumara\u003c/em\u003e River are Nitisols, Vertisols, Gleysols, Luvisols and Cambisols (Temesgen Gashaw et al., \u003cspan class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003e2.3 Land Use and Farming Systems\u003c/h2\u003e\n \u003cp\u003eThe dominant land use and land cover classes in the study watershed are cultivated land, grazing land, forest (natural), Eucalyptus plantation (woodlots), bare land and rehabilitated land. The total area covered by the \u003cem\u003estudy\u003c/em\u003e watershed is estimated to be 120.47 ha, of which 51.84 ha is arable land, 16.68 ha is grazing land and 23.6 ha is forest, 15.38 ha is rehabilitated land and 0.85 ha is bare land. The topography of the \u003cem\u003earea\u003c/em\u003e comprises 25% plain, 60% undulating, 5% gorge and valley, and 10% mountainous. The farming system in the study area is predominately crop production, mixed with animal production. Teff, finger millet, wheat, maize, barley, rice and potato are the major crops grown in the district but teff and wheat are the major crops cultivated in the study watershed (Van Beek et al., \u003cspan class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003e2.4 Sampling Design and Sample Size\u003c/h2\u003e\n \u003cp\u003eIn order to collect the required data needed to achieve the objectives of the research, a different data collection method through random sampling (RS) were employed. The study watershed was selected purposively as it is the study area of the BDU-IUC programme particularly the land Resilience project. From the selected \u003cem\u003ekebele\u003c/em\u003e two micro small catchments were selected in such a way that the catchments represent the district in biophysical, agricultural and socio-economic aspects. Most importantly the watershed was selected so that they represent the main farming practices, crop varieties, socio economic status, and topographic features. Accordingly, \u003cem\u003eenkulal\u003c/em\u003e watershed was selected from \u003cem\u003eGelawudewos kebele\u003c/em\u003e. This watershed has two small catchments and each catchment has different land cover classes. Sampling micro-catchments were selected to monitor nutrient flow in and out of the system and finally to analyze partial nutrient (N, P, and K) balance.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003e2.5 Data Collection\u003c/h2\u003e\n \u003cp\u003eThe information required for nutrient balance analyses come from a mixture of sources. Obviously, the most precise was involving direct measurements of the amounts of nutrients transferred in and out through each factor. Nutrient outputs by crop product (OUT1), crop residue (OUT2) were considered under direct measurement in the field.\u003c/p\u003e\n \u003cp\u003eFocus group discussions were conducted in the selected watershed area. Eight farmers were selected randomly from the selected watershed to collaborate in a soil fertility experiment and a household survey. This activity was used as a tool to identify major cropping systems, type of input and outputs, and crop production problems. These data were used to determine annual nutrient inflows and outflows for each plot and the farm as a whole. In case of outflow, survey data was used to know the biomass of crop residue and for what purpose they collected to their home. Finally these flows were used to compute the nutrient balance for each land use for one year (Van Beek et al., \u003cspan class=\"CitationRef\"\u003e2003\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003e2.6 Quantification of Nutrient Inputs and Outputs\u003c/h2\u003e\n \u003cp\u003eThe information required for nutrient balance analyses come from a mixture of sources. Nutrient output by crop product (OUT1), crop residue (OUT2) and erosion (OUT5) were considered under direct measurement in the field. However, direct measurement was not possible for some inputs including wet deposition (IN3), nitrogen fixation (IN4) and outputs (leaching-OUT3, gaseous losses-OUT4). In such cases, inputs and outputs were estimated with transfer function. The amount of fertilizer applied was accounted through interviews and secondary data sources to calculate and convert the total amount of fertilizer into corresponding quantities of nutrients (Aticho et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eInputs for N, P, K, primary data was obtained on type and amount of mineral fertilizer (IN1), organic inputs (IN2), whereas atmospheric deposition (IN3) and biological nitrogen fixation (IN4) were estimated by transfer function. Field observations were made on type and amount of input and output, type of cereal crop grown and their grain and residue yield were recorded. Atmospheric deposition of N was estimated as total agricultural land area multiplied by a single coefficient of N deposited per hectare. Non-symbiotic N fixation was calculated according to Lesschen \u003cem\u003eet al.\u003c/em\u003e(2007).\u003c/p\u003e\n \u003cp\u003eThe nutrient (N, P and K) balances were calculated from a combination of four input and five output flows using a re-assign equation (Stoorvogel and Smaling, 1998). Quantification of the N, P and K in the input and output flows were achieved through the combination of different methods: field measurement, use of empirical quantitative relations (\u003cem\u003ei.e.\u003c/em\u003e transfer functions) and assumptions based on secondary data from a variety of sources (Kiros et al., \u003cspan class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eN, P and K content was determined in laboratory following standard procedures (Aremu et al. (\u003cspan class=\"CitationRef\"\u003e2006\u003c/span\u003e). The quantity of N, P and K added to farm in the form of different inputs were obtained by multiplying dry weight of each input material with its nutrient content. Plant litter fall was taken as an input source in the forest. N, P and K added to the soil with wet deposition (IN3) was estimated with the equation developed by Smaling et al. (\u003cspan class=\"CitationRef\"\u003e1993\u003c/span\u003e) which is a function of mean annual rainfall (mm yr \u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). The mean annual rainfall (p) was obtained from the nearby meteorological stations (Arb Gebya Meteorology Station).\u003c/p\u003e\n \u003cp\u003eIN3 N\u0026thinsp;=\u0026thinsp;0.14P\u003csup\u003e1/2\u003c/sup\u003e (1)\u003c/p\u003e\n \u003cp\u003eIN3 P\u0026thinsp;=\u0026thinsp;0.023P\u003csup\u003e1/2\u003c/sup\u003e (2)\u003c/p\u003e\n \u003cp\u003eIN3 K\u0026thinsp;=\u0026thinsp;0.092P\u003csup\u003e1/2\u003c/sup\u003e (3)\u003c/p\u003e\n \u003cp\u003eThe percentages of total N uptake through symbiotic N fixation by leguminous crops were reported in different literature. Studies conducted in different parts in Ethiopia show that 60% of legume plant N requirement is met by symbiotic nitrogen fixation (Aticho et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e). However, no literature was available for non-symbiotic N fixation and N-fixing trees that are left on the field. Therefore, this input was estimated on the basis of the amount of rainfall using the transfer function (Smaling et al., \u003cspan class=\"CitationRef\"\u003e1993\u003c/span\u003e) as follows:-\u003c/p\u003e\n \u003cp\u003eIN4\u0026thinsp;=\u0026thinsp;0.5\u0026thinsp;+\u0026thinsp;0.1P\u003csup\u003e1/2\u003c/sup\u003e (4)\u003c/p\u003e\n \u003cp\u003eWhere, N fixed is expressed in kilograms of N per hectare and year, and P is mean annual precipitation in mm yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003e2.7 Quantifying outputs from farmland and other land uses\u003c/h2\u003e\n \u003cp\u003eRemoval of harvested products (OUT1), crop residues (OUT2), leaching (OUT3), gaseous lose (OUT4) and erosion (OUT5) are usually the major pathways of nutrient losses from agricultural soils. The amount varies considerably depending on crop type, soil type, agronomic practices and plant nutrient uptake (Brady and Weil, \u003cspan class=\"CitationRef\"\u003e2008\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003e➢ Output quantification from harvested product (OUT1):\u003c/p\u003e\n \u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e$$\\text{O}\\text{U}\\text{T}1=\\sum \\frac{(\\text{a}\\text{r}\\text{e}\\text{a}\\times \\text{n}\\text{u}\\text{t}\\text{r}\\text{i}\\text{e}\\text{n}\\text{t} \\text{c}\\text{o}\\text{n}\\text{t}\\text{e}\\text{n}\\text{t}\\times \\text{y}\\text{i}\\text{e}\\text{l}\\text{d})}{\\text{T}\\text{o}\\text{t}\\text{a}\\text{l} \\text{a}\\text{r}\\text{e}\\text{a}}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eTN\u0026thinsp;=\u0026thinsp;Y\u0026times;N\u0026thinsp;=\u0026thinsp;kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (6)\u003c/p\u003e\n \u003cp\u003eP\u0026thinsp;=\u0026thinsp;Y\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eP\u0026thinsp;=\u0026thinsp;kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (7)\u003c/p\u003e\n \u003cp\u003eK\u0026thinsp;=\u0026thinsp;Y\u0026times;K\u0026thinsp;=\u0026thinsp;kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (8)\u003c/p\u003e\n \u003cp\u003eWhere, Y\u0026thinsp;=\u0026thinsp;yield (kg/ha), N\u0026thinsp;=\u0026thinsp;N content of crop (% harvested product); P\u0026thinsp;=\u0026thinsp;P content of crop (ppm harvested product), and K\u0026thinsp;=\u0026thinsp;K content of crop (ppm harvested product).\u003c/p\u003e\n \u003cp\u003e➢ Output quantification from crop residue/straw (OUT2)\u003c/p\u003e\n \u003cp\u003eN\u0026thinsp;=\u0026thinsp;R \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eN = (kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (9)\u003c/p\u003e\n \u003cp\u003eP\u0026thinsp;=\u0026thinsp;R \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003e P = (kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (10)\u003c/p\u003e\n \u003cp\u003eK\u0026thinsp;=\u0026thinsp;R \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003e K = (kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (11)\u003c/p\u003e\n \u003cp\u003eWhere, R\u0026thinsp;=\u0026thinsp;amount of residues (kg/ha); N\u0026thinsp;=\u0026thinsp;N content of crop residues (kg N/ kilograms of harvested product); P\u0026thinsp;=\u0026thinsp;P content of crop residues (kg P/ kilograms of harvested product); K\u0026thinsp;=\u0026thinsp;K content of crop residues (kg K/ kilograms of harvested product).\u003c/p\u003e\n \u003cp\u003eThe amount of crop products (OUT1) and residues (OUT2) exported from farm section were determined by randomly demarcating 3 sample plots of each common crop (\u003cem\u003eteff\u003c/em\u003e and wheat) from the study area (each plot had 1 m\u003csup\u003e2\u003c/sup\u003e area). At crop maturity, crops in the sample plots were harvested, sun dried, trashed and weighed with hand held balance and composite samples had been taken for laboratory analysis. The amount of N, P and K exported by OUT1 and OUT2 were calculated by multiplying the total amount of crop product and residue exported from farm with their respective N, P and K content (Stoorvogel \u003cem\u003eet al., 1993)\u003c/em\u003e. Substantial amounts of N and K are lost through leaching (OUT3) but not P as it strongly bounds with soil particle (Laird \u003cem\u003eet al.\u003c/em\u003e, 2010). N and K losses through leaching were not directly measured; rather a transfer function was used (Stoorvogel and Smaling, \u003cspan class=\"CitationRef\"\u003e1990\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eOUT3N\u0026thinsp;=\u0026thinsp;2.3+ (0.0021\u0026thinsp;+\u0026thinsp;0.0007\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eF).P\u0026thinsp;+\u0026thinsp;0.3.IN1\u0026thinsp;+\u0026thinsp;IN2-0.1\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eTNU (12)\u003c/p\u003e\n \u003cp\u003eOUT3 K = (0.6+ (0.0011\u0026thinsp;+\u0026thinsp;0.002\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eF).P\u0026thinsp;+\u0026thinsp;0.5. (IN1\u0026thinsp;+\u0026thinsp;IN2)-0.1\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eTKU)/1.2 (13)\u003c/p\u003e\n \u003cp\u003eWhere, P: mean annual rainfall, F: soil fertility class (1\u0026thinsp;=\u0026thinsp;low; 2\u0026thinsp;=\u0026thinsp;moderate; 3\u0026thinsp;=\u0026thinsp;high), IN1 andIN2: mineral fertilizer and manure applied (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) respectively, TNU and TKU: total N and K uptake (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), respectively.\u003c/p\u003e\n \u003cp\u003eNitrogen lost from agricultural soils in the form of denitrification and volatilization is considered as gaseous loss (OUT4) (Stoorvogel and Smaling, \u003cspan class=\"CitationRef\"\u003e1990\u003c/span\u003e). Similar with leaching, direct measurement of N loss in gaseous form is difficult thus it was estimated by regression equation (Aticho et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eOUT4\u0026thinsp;=\u0026thinsp;(0.025\u0026thinsp;+\u0026thinsp;0.000855\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003eP+0.01725 \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003e IN1\u0026thinsp;+\u0026thinsp;IN2\u0026thinsp;+\u0026thinsp;0.117) + (0.113 \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\times\\)\u003c/span\u003e\u003c/span\u003e IN1\u0026thinsp;+\u0026thinsp;IN2) (14)\u003c/p\u003e\n \u003cp\u003eWhere, P\u0026thinsp;=\u0026thinsp;mean annual rainfall; IN1\u0026thinsp;+\u0026thinsp;IN2: mineral fertilizer and manure applied (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr \u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), respectively.\u003c/p\u003e\n \u003cp\u003eNutrient outflow due to soil erosion (OUT5) was directly measured. First the total runoff coming out of the catchments estimated using a 90\u003csup\u003eo\u003c/sup\u003e v-notch weir. Continuous sediment samples were done over the rainy season. The nutrients lost as suspension and sediment fixed were calculated in the lab. Total amount of nutrient lost with erosion were then quantified by the sum of nutrient losses which is dissolved with the runoff water after the sediment is filtered and nutrient loss along with the sediment. The amount of discharge for general sharp crested triangular weir with angle \u0026theta; is calculated as described below (Piratheep\u003cem\u003eet al\u003c/em\u003e., 2006).\u003c/p\u003e\n \u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e$$Q=\\frac{8}{15}\\sqrt{2g}{C}_{d}{\\text{tan}}^{\\left(\\raisebox{1ex}{$\\theta $}\\!\\left/ \\!\\raisebox{-1ex}{$2$}\\right.\\right)}{h}_{e}^{\\left(\\raisebox{1ex}{$5$}\\!\\left/ \\!\\raisebox{-1ex}{$2$}\\right.\\right)}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e15\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\n \u003cdiv class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e$${h}_{e}={h}_{U}+{k}_{h}$$\u003c/div\u003e\n \u003cdiv class=\"EquationNumber\"\u003e16\u003c/div\u003e\n \u003c/div\u003e\n \u003cp\u003eWhere:\u003c/p\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eQ (m\u0026sup3;/s) is flow over v-notch weir\u003c/p\u003e\n \u003cp\u003e𝐶\u003csub\u003ed\u003c/sub\u003e is discharge coefficient\u003c/p\u003e\n \u003cp\u003eK\u003csub\u003eh\u003c/sub\u003e is correction factor for the head\u003c/p\u003e\n \u003cp\u003eh\u003csub\u003ee\u003c/sub\u003e is effective head of the weir\u003c/p\u003e\n \u003cp\u003eh\u003csub\u003e𝑢\u003c/sub\u003e (m) is the head flowing through the notch\u003c/p\u003e\n \u003cp\u003e\u0026theta; (degrees) is the notch angle\u003c/p\u003e\n \u003cp\u003eg is the acceleration of gravity (9.81 m/s\u0026sup2;)\u003c/p\u003e\n \u003c/div\u003e\n \u003cp\u003eThis equation has been simplified for a 90\u003csup\u003eo\u003c/sup\u003e sharp crested v-notch (Rantz, 1982), and was used in this study using Eq.\u0026nbsp;17.\u003c/p\u003e\n \u003cp\u003eQ\u0026thinsp;=\u0026thinsp;2.49h\u003csub\u003ee\u003c/sub\u003e\u003csup\u003e2.48\u003c/sup\u003e (17)\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n \u003ch2\u003e2.8 Laboratory analysis\u003c/h2\u003e\n \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e\n \u003ch2\u003e2.8.1 Runoff water sample collection and analysis\u003c/h2\u003e\n \u003cp\u003eRunoff stage was recorded every five minutes from the outlets of each land use/land cover class during rain events, which were later composited on a monthly basis. After collection, runoff samples were filtered and air dried. The sediment were filtered by Whatman filter paper, air-dried, sieved by 2 mm sieve and analyzed by following standard laboratory procedures while, the nutrient in the water was thoroughly mixed and re-sampled for the nutrient analysis from solution. The NPK contents of both plants and soil were analyzed in Amhara Design and Construction Enterprise laboratory.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n \u003ch2\u003e2.8.2 Plant sampling and analysis\u003c/h2\u003e\n \u003cp\u003eTo determine OUT1 and OUT2, a 1 m\u003csup\u003e2\u003c/sup\u003equadrant were used for sampling teff, wheat and litter fall. Fresh crop biomass was weighed immediately after harvest using field balance, crop grain was collected and weight of grain and straw was measured separately, and then both straw and grain were taken for laboratory analysis. The plant material was prepared through drying at a maximum of 60 to 70\u0026deg;C, grinded to pass through a 0.15 mm mesh (Anderson \u0026amp; Ingram, 1993). Total nitrogen was determined by Kjeldahl method (Kirk, P.L.1950) Phosphorus was determined colorimetrically by using molybdate and metavandate for color development (van Reeuwisk, L. 1992). Potassium (K) was determined by flame photometer (Morgan, \u003cspan class=\"CitationRef\"\u003e1941\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003eSoil nutrient contents were also determined using standard method; available P was extracted by Olsen method (Olsen and Dean, \u003cspan class=\"CitationRef\"\u003e1965\u003c/span\u003e), and P was then determined using spectrophotometer;total nitrogen was determined by Kjeldahl method and available potassium (K) was extracted by Morgan\u0026rsquo;s solution and K in the dissolved solution was measured by flame photometer.\u003c/p\u003e\n \u003cp\u003eTo determine the amount of nutrient input in the form of animal manure on the grazing land, the amount of available manure were derived from the number of livestock within the study area, using excretion, nutrient content and loss factors. The amount of manure sample needed to analyze each nutrient in the laboratory was similar as described above. Nutrients in manure as excreted for all livestock were estimated by multiplying the quantity of manure excreted (wet weight) times the nutrient content of manure excreted. But, N loss directly from livestock (e.g. ammonia volatilization from stored manure) is not included in the balance, although livestock manure production is a major source of N input. Livestock manure N production: total numbers of live animals multiplied by respective coefficients of the quantity of N contained in manure per animal per year. Composite samples of fresh manure from the grazing land were collected and analyzed for composition of N and P in laboratory. The manure samples were oven dried at 105\u0026deg;C before analysis (Saleem, \u003cspan class=\"CitationRef\"\u003e1998\u003c/span\u003e).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e\n \u003ch2\u003e2.8.3 Nutrient balance analysis\u003c/h2\u003e\n \u003cp\u003eNitrogen, phosphorus and potassium (kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) balance were obtained by subtracting the quantity of NPK removed from soil through crop products (OUT1), crop residues (OUT2), leaching (OUT3), gaseous lose (OUT4) and erosion (OUT5) from the total amount of N, P and K added to the system with mineral fertilizer (IN1), manures (IN2), biological nitrogen fixation (IN3), and wet deposition (IN4) (Smaling et al., \u003cspan class=\"CitationRef\"\u003e1998\u003c/span\u003e).\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"3. RESULTS AND DISCUSSION","content":"\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Nutrient Inflow in to the Catchments\u003c/h2\u003e \u003cp\u003eAccording to the information obtained through discussion with farmers, the only fertilizers applied by the farmers in the study area were urea and NPS. The fertilizer rate used by the farmers was known by interviewing the teff and wheat producing farmers found in the area. The amount of fertilizer used by the farmer in the study area was 120 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e NPS for teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) cropland and 100 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e NPS and 60 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e urea for wheat cropland. The use of fertilizer in the study area was better compared to the national average rate of 43 kg urea ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 65 kg DAP ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Elias et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Except their farm yard plot, farmers in the study area did not apply animal manure and compost to their main arable land. This could be influenced by their settlement location which creates inconveniencies to prepare and transport manure, use of dung for household energy, and its small quantity which is only enough to their backyard lands. Nutrient input and output of each land use and land cover (LULC) is different. For instance, in farming system crop product (OUTPUT1) and residue (OUTPUT 2) were taken in to account as a special nutrient output from the other LULC. Similarly, plant litter fall and animal manure are type of nutrient inputs for the natural forest and grazing land respectively. Unlike the other land use system, inorganic fertilizers were the major nutrient input for cultivated land in the study area.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNutrient inflow (TNIN) on Teff and Wheat cropland\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCropping Land\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMineral Fertilizer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOrganic Fertilizer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWet Deposition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNitrogen Fixation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003eTotal Nutrient Input\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN P\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTeff\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.7 19.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e31.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e20.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWheat\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.2 16.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e59.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e17.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe nutrient inputs from NPS fertilizer for teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) cropland were estimated at 22.7 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 19.8 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. While the nutrient inputs added to wheat cropland was estimated 50.3 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eand 16.5 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Wet deposition (IN3) and nitrogen fixation (IN4) were the other nutrient inputs considered in this study. In reality, teff and wheat are not leguminous crops but all crops benefit from N that is settled non-symbiotically which performed by blue green algae and free-living bacteria, most particularly (Azotobacter, Beijerinckia and Clostridium) or by N-fixing trees that are cleared out on the field (Rhizobia and Actinomycetes spp.) (Aticho et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). The value of nitrogen added to the farm through wet deposition (IN3) and nitrogen fixation (IN4) for both croplands were estimated to be 5 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 4 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e respectively. However, the P and K inputs due to wet deposition were only 0.8 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 3.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e obtained from the pedo transfer function (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The nutrient inputs from NPS fertilizer in the present study was very high compared to the national level (Haileslassie et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e) which was estimated to be 12.24 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 12.87 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe sequence of total N, P and K inputs (TNIN, TPIN, TKIN) for teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) crop land from all sources (inorganic fertilizer, wet deposition and nitrogen fixation) was 31.7 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 20.6 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 3.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and for wheat cropland it was 59.2 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 17.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 3.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e ( Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Hence, the phosphorus inputs were higher for teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) while nitrogen was higher for wheat cropland. Because, this high amount of nitrogen for wheat crop was mainly due to the application of NPS. However, the high amount of P content which was estimated in teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) cropland might be due to the use of higher level of P (38%) in 100 kg of NPS during sowing time. NPS fertilizer also contains 7% of sulfur from the total proportion but in the present study we did not analyze sulfur rather we focused on only the three primary nutrients (N, P and K). These values were obtained from the standardized proportion of NPS which had the consecutive rate of 19:38:7. The potassium level added to the system was no not analyzed as potassium is not scarce in the Ethiopian soils. Due to this reason the common source of K nutrient input for each land use was wet deposition obtained by pedo transfer function (Equ. 7). But, livestock manure for grazing land and leaf litter fall for forest land also contributed some amount of potassium.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNutrient input into different land use land cover type (kg ha \u003csup\u003e-1\u003c/sup\u003e yr \u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLand Use Land Cover Type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMineral Fertilizer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOrganic fertilizer\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eWet Deposition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNitrogen fixation\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNatural Forest\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15.3 2.3 0.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrazing land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.4 0.1 6.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBare land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRehabilitatedland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5 0.8 3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAs described in the above paragraph, in addition to biological nitrogen fixation and wet deposition, plant litter fall were considered for natural forest instead of organic fertilizer for cultivated land which is used as INPUT2. As observed in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, Litterfall is the dominant pathway for nutrient return to the soil, especially for nitrogen (N) and phosphorus (P).However, in bad land area no plant species was provided and the nitrogen input through symbiotic fixation was nil. To estimate the amount of nutrient input to the grazing land, the number of livestock, the length of time keeping on that controlled grazing land and the average amount of dung/muck per day to estimate the N, P and K nutrient content of animal manure were asked from the local farmers. On average three livestock were kept in the study grazing plot area. The cattle spent ten hours in the field per day and a single cow drops its defecations three times a day equivalent to 1.2 kg as fresh animal dung and 0.3 kg dry matter dung as estimated in the study plot. Animals may graze outside these two catchments in dry season after the crop is harvested. However, in cropping (summer) season, they are kept in the specified catchment. In dry season people also collect their domestic fuel wood outside these two catchments and housewives use part of the animal droppings for domestic energy purposes. Actually, the loss of animal dropping in these multiple ways make a fallacy on annual nutrient balance in grazing land. Nevertheless, to recover this misleading value of nutrient balance, we used 15% removal factor during nutrient (N, P and K) quantification (Saleem, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e1998\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eForests receive a high amount of nutrient inputs from plant litter fall which was taken into account as INPUT2 and amount of N, P and K estimated from plant litter fall was 15.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 2.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 0.24 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e respectively. Atmospheric deposition and nitrogen fixation were the other major nutrient input mechanisms into the land use system. The value estimated from atmospheric deposition was 5 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.8 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 3.3 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 4 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e via nitrogen fixation (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The results of N, P and K INPUT estimated from wet deposition and nitrogen fixation in this study were comparable to similar other studies (Haileslassie et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Nutrient Outflow from the Catchment\u003c/h2\u003e \u003cp\u003eFrom the cultivated land, the main nutrient outflows were in the form of crop harvested product and crop residue/straw. In this study, it was estimated 17.2 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 2.8 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.16 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e losses in harvested product (OUT1) for teff (\u003cem\u003eEragrostis tef\u003c/em\u003e) and 17 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 9.5 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 0.17 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for wheat cropland. Whereas, the losses of N, P and K via crop residues (OUT2) were 22.8 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 6 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.9 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for teff and 11.9 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 8.01 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.4 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for wheat cropland respectively (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). In the present study, the loss of potassium level from crop product and crop residue was very low compared to the study by Haileslassie et al. (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). The higher depletion of K in the preceding one could be associated with continuous cultivation, total evacuation of crop residues from farmlands, absence of crop rotation, unequal fertilizer application, soil disintegration, misfortune of organic matter (OM) and insufficient fertilizer application (Laekemariam \u003cem\u003eet al.\u003c/em\u003e, 2018). Kiros et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e) also reported the losses of N, P and K via harvested crops (OUT1) at the catchment level were varied from 28.69\u0026ndash;82.64 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.12\u0026ndash;0.32 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 9.37\u0026ndash;18.02 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e respectively across the different landscapes and socio-economic groups respectively. However, the three macro-nutrient losses through crop yield in the present study were very low compared to other studies (Kiros et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). In the previous studies, nutrient outflow quantification was undertaken in more cereal crops including teff and wheat and in different landscapes. Agroecology, soil type, amount of nutrient input or fertilizer application rates, area coverage, precipitation and amount of runoff also can be the other factor to contradict the nutrient loss from similar land use between the current study and similar other studies.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eNutrient output from each land use land cover type (kg ha \u003csup\u003e-1\u003c/sup\u003e yr \u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLand\u0026nbsp;Use/Land Cover Type\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCrop yield\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCrop residue\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLeaching\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGaseous loss\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSoil erosion\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN K\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eN P K\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ewheat cropland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17 9.5 0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.9 8.01 0.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15.6 26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28 0.5 14.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTeff cropland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17.2 2.8 0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.8 6 0.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.1 14.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e39 0.7 14.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRehabilitated land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.8 5.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e36.1 1.07 5.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBadland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.8 5.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e50.6 1.18 18.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrazing land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.7 7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e43.8 0.55 4.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNatural Forest\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 0 0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e19.5 6.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e31.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.38 0.31 2.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows that the major nutrient outputs from cultivated land were crop yield (OUT1), crop residue (OUT2), and erosion (OUT5). Higher N, P, K losses having the corresponding value (22.8 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr \u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 6 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.9 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) were observed in crop residue than in crop yield ( 17.2 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 2.8 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0.16 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) in teff cropland as a result of higher biomass of crop residue (straw)ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e obtained compared to its grain product. The estimated value of N, P, K losses through crop residue in this study differ from the findings by Kiros et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). But for the other fields leaching (OUT3), gaseous losses (OUT4) including erosion (OUT5) were identified as a common nutrient output from the system. Among the different land use/land covers, higher nutrient lose by erosion (OUT5) was recorded due to the presence of higher erosion from the area. Comparably, higher N nutrient losses had been estimated in soil erosion than the other output pathways (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). In general, nitrogen and potassium loss through erosion were higher as compared to phosphorus, as N and K are mobile nutrients and easily transferred through erosion (Bekunda et al., \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). As observed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, however, phosphorus is an immobile nutrient although some amount is generally transferred to water through sediment-based runoff or erosion.\u003c/p\u003e \u003cp\u003eSimilarly, phosphorus depletion is negligible in leaching compared to N and K. Leaching losses of N and K in wheat were higher than teff crop land. Unlikely, leaching losses were lower in rehabilitated land and bad land compared to all land use/land covers (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). This inconsistency may be due to the low amount of soil water nutrient concentration, soil physical characteristics, climate, rainfall intensity, low soil moisture, and poor water retention capacity of soils. N losses via denitrification (OUT4) from cereal crops (7.6 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in wheat and 4 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in teff crop land)were comparable to the finding by Haileslassie et al., (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e) (5.6 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). This can be the use of the same way of estimation, presence of similar amount of annual precipitation and amount of input and output value contributed in the equation. Because average annual precipitation, nutrient input and outputs are the major components used during nitrogen loss estimation through denitrification (Eq.\u0026nbsp;11).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Nutrient Balances on different land use/land covers\u003c/h2\u003e \u003cdiv id=\"Sec18\" class=\"Section3\"\u003e \u003ch2\u003e3.3.1 Partial nutrient balance on cultivated land\u003c/h2\u003e \u003cp\u003ePartial nutrient balances estimated for agricultural lands are basically anthropogenic balances, and do not take into account natural mechanisms like wet deposition, nitrogen fixation, leaching, and gaseous loss. The partial nutrient balances (aggregated by teff and wheat cropland), which is the difference between sum of outputs (OUT1\u0026thinsp;+\u0026thinsp;OUT2) and sum of inputs (IN1\u0026thinsp;+\u0026thinsp;IN2) (Haileslassie et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). However, in this study the value of N, P and K nutrient from organic fertilizer (IN2) were zero because the farmers did not apply animal manure or compost in their farmland.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePartial nutrient balances for teff and wheat cropland (kg ha\u003csup\u003e-1\u003c/sup\u003e yr\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLand Use\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eIN1\u0026thinsp;+\u0026thinsp;IN2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003eOUT1\u0026thinsp;+\u0026thinsp;OUT2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003ePartial Balance\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eK\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTeff\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-17.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-1.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWheat\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e17.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e21.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe consequence of the partial nutrient balance proved that the nutrient removals by the crop harvest and crop residues were the most contributors to the N and K negative partial balances in both croplands. The N, P and K partial balances for teff cropland were estimated \u0026minus;\u0026thinsp;17.3 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, +\u0026thinsp;11 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -1.06 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e respectively. However, for wheat cropland\u0026thinsp;+\u0026thinsp;21.3 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -1 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -0.57 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e were estimated (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Even if the partial nitrogen for teff and phosphorus nutrient balance indicated positive in wheat crop production system, the value implied was at warning to become negative balance for the future unless the nutrient management is improved. The partial balance of potassium content observed in this study is slightly negative in both croplands. This does not imply that potassium mining from the area is low as this only shows the partial nutrient balance of a wheat farm. The same is true that, positive N partial balance for wheat and P for teff cropping land is not the indication for nutrient accumulation in the area.\u003c/p\u003e \u003cp\u003eBased on the partial input-output nutrient balance, the study area shows phosphorus had positive partial balances for both croplands. Wheat farming system had positive nitrogen partial balances and negative for teff. Unlike N and K, a positive balance of P was observed in both agricultural lands. Except the nitrogen balance for wheat which was positive, this study is in line with the finding of other studies (Haileslassie et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Kiros et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Therefore, net negative soil nitrogen balances in teff cropland represent a significant concern to the long-term sustainability of soil resource in a broad context that extends beyond soil nutrient availability (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e3.3.2 Full nutrient balances\u003c/h2\u003e \u003cp\u003eUnlike the partial nutrient balance which was calculated by considering only anthropogenic ways of nutrient input and output, the full nutrient balance were quantified by using both anthropogenic and natural mechanisms like wet deposition, nitrogen fixation, leaching, and gaseous loss of nutrient import and export. Therefore, the full nutrient balances were estimated by considering the difference between total nutrient output from the total nutrient input (total nutrient input-total nutrient output) (Stoorvogel and Smaling, 1998).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eTotal nutrient inputs and outputs (kg ha \u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr \u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) for different land use/land cover type\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLULC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eTotal Nutrient input\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eTotal Nutrient Output\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTNIN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTPIN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTKIN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTNOUT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTPOUT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eTKOUT\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTeff Crop land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e93.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWheat Crop land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e59.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e80.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e18.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e41.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNatural Forest\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e62.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e9.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGrazing land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e63.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBad land\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e57.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e23.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRehabilitatedland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e10.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003eHint: TNIN\u0026thinsp;=\u0026thinsp;total nitrogen input, TPIN\u0026thinsp;=\u0026thinsp;total phosphorus input, TKIN\u0026thinsp;=\u0026thinsp;total potassium input\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e summarizes the total nutrient inputs and outputs for the major crops (teff, wheat) and other land use/land covers found in the study sub-catchments. As compared to the other nutrients, N balances indicated higher negative value for each land use/land cover. Because, nitrogen is very susceptible to loose in all output mechanisms. The full nutrient balance results were different across the six land use/land covers. In this study, negative nitrogen and potassium balances were observed in all land use and land covers. The full balances for the major cropland mainly wheat and teff were estimated to be -20.9 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -0.7 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -37.87 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for wheat and \u0026minus;\u0026thinsp;61.4 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, +\u0026thinsp;11 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and \u0026minus;\u0026thinsp;26.7 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for teff cropland (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). As observed in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, higher negative balances were found in teff cropping land and badland. Because higher nutrients especially nitrogen were lost from these two land use/land cover through erosion (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). In wheat cropland, rehabilitated and badland, the phosphorus balances indicated slightly negative (-0.7, -0.27 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and \u0026minus;\u0026thinsp;0.38 kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003ecorrespondingly) whereas the other LULC had positive P balances (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The possible reason to become negative nutrient balance in natural forest may be the increasing of biomass demand, animal disturbance, and higher infiltration leads to higher nutrient removal through leaching. And these problems can be avoided by decreasing biomass harvest intensities, recycling harvest leftovers and area closure.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e3.4 Discussion\u003c/h2\u003e \u003cp\u003eThe partial balances of N, P and K in this finding is in agreement with the study by Haileslassie et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2006\u003c/span\u003e) for teff cropland but it differs for wheat cropland which was estimated \u0026minus;\u0026thinsp;9 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 8 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -11 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and \u0026minus;\u0026thinsp;21 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 0 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eyr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -21 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for the corresponding nutrient type and cropping land by the previous one. The reason for the variation of partial nutrient balance in wheat cropland may be due to differences in the amount and type of fertilizer application, soil and water conservation, and nutrient management practices. Except for P, the partial N and K balances in this study are in agreement with other studies for teff while it differs for wheat crop land (Haileslassie \u003cem\u003eet al.\u003c/em\u003e, 2007) who reported \u0026minus;\u0026thinsp;50 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e,-8 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -41 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (for wheat) and \u0026minus;\u0026thinsp;8 kg N ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, +\u0026thinsp;10 kg P ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, -16 kg K ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for teff crop land.\u003c/p\u003e \u003cp\u003eHowever, this study contradict with the study by Haileslassie et al. (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e) who reported positive partial nutrient balances for the Tigray Region (+\u0026thinsp;10 N, +\u0026thinsp;6 P, +\u0026thinsp;10 K kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e ) and for Ethiopia (+\u0026thinsp;10 N, +\u0026thinsp;11 P, +\u0026thinsp;7 K kg ha\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e yr\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e ) at national level. The current study shows a lower estimate compared to the national level. The lower estimates reported in this study might be due to the lack of organic fertilizer application. The results of the partial nutrient balance showed that the nutrient removals by the crop harvest and crop residues were the greatest contributors to the N and K negative balances in teff cropland. Positive nitrogen partial balance in wheat cropland and positive phosphorus partial balance in both croplands were observed in this study. The negative N partial balance in teff cropland may be associated with the removal of higher biomass of crop residue from the area. The level of potassium in the balance was negative for both crops. This may be due to the absence of potassium fertilizer and other K inputs to the farm. The only source of potassium in the farm was through wet deposition (IN3) which was estimated using transfer function.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e3.5 SUMMARY, CONCLUSION AND RECOMMENDATION\u003c/h2\u003e \u003cp\u003eNutrient inputs, outputs and nutrient balances from this study show that soil nutrient depletion is a major problem in the study area. Particularly N and K showed negative balances in all the land uses primarily due to large removals of nutrients by erosion, harvested output, crop residue, leaching and gaseous loss due to poor nutrient management. The findings also showed that nutrient depletions were more severe in the crop lands than the other land uses. Nutrient losses through crop harvest (grain and straw) contribute the most important sources of nutrient mining. Nutrient losses along with soil erosion by water were identified the dominant factor for nutrient depletion in all land uses which was measured based on nutrient content in the eroded sediments and as dissolved nutrients in the runoff water. Especially nitrogen loss was higher through erosion which could be caused by the mobile nitrate. It was distinguished that nutrient losses were much higher in the runoff water (dissolved) compared to the sediment bounded nutrients. There was seasonal variation in the quantities of nutrient export through soil erosion from each land use/land cover.\u003c/p\u003e \u003cp\u003eThe partial nutrient balances for teff cropland were strongly negative than wheat. Because without the potassium balance indicated slightly negative, N and P had positive partial balances for wheat crop land. N and K had negative nitrogen full balance for both cropping system whereas with the exception of rehabilitated and bare land, phosphorus had positive balance. Unlike partial balances for wheat cropland which had positive nitrogen balance, full balances were negatives compared to partial nutrient balances, full nutrient balances had negative nitrogen and potassium value for all land use/land cover because nutrients in the full balance were lost largely through leaching, denitrification, runoff and sediment transport. Consequently, the study area needs improvements in nutrient use efficiency from different inputs, awareness creation through integrated nutrient management to mitigate nutrient removal and there by improve the sustainability and productivity of the system. The information on flow of nutrients and their balance in different land use can be used for future management of the systems for their sustainable production. In general, the negative partial and full balances observed in cultivated land and other land uses were used as indicators for improvements in soil fertility management.\u003c/p\u003e \u003cp\u003eFurther nutrient balance analysis studies should be promoted at different spatial scale to identify the level of nutrients in the soil and to determine proper nutrient management practice and to recommend appropriate rates and types of fertilizer application with a little impact on the environment or water quality of water bodies. The study also identified that nutrients are transported to the atmosphere, ground water and to the surface water. Thus, proper nutrient application methods and land use management should be further studied to reduce the risk of nutrient transport to surface and ground water, or into the atmosphere.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data used to support the findings of this study are available from the corresponding author upon request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank Bahir Dar University Institutional University Cooperation (BDU-IUC) Programme and Debre Markos University for providing financial support for the data collection and for the write up of the result of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Bahir Dar University Institutional University Cooperation (BDU-IUC) Programme and Debre Markos University is gratefully acknowledged for supporting this research. \u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAremu, M. 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R. 2008.\u0026nbsp;\u003cem\u003eThe nature and properties of soils\u003c/em\u003e (Vol. 360): Pearson Prentice Hall Upper Saddle River.\u003c/li\u003e\n \u003cli\u003eDe Jager, A. 2005. Participatory technology, policy and institutional development to address soil fertility degradation in Africa. \u003cem\u003eLand Use Policy, 22\u003c/em\u003e(1), 57-66.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eElias, E., Okoth, P. F., \u0026amp;Smaling, E. M. A. (2019). Explaining bread wheat (Triticum aestivum) yield differences by soil properties and fertilizer rates in the highlands of Ethiopia. \u003cem\u003eGeoderma\u003c/em\u003e, \u003cem\u003e339\u003c/em\u003e, 126-133.\u003c/li\u003e\n \u003cli\u003eGashaw, T., Bantider, A., \u0026amp;Mahari, A. (2014). 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M., Lynam, J., \u0026amp; Nandwa, S. 1998.\u0026nbsp;Nutrient balances as indicators of productivity and substainability in Sub-Saharan African agriculture: Papers Presented during the conference Soil Fertility Management in Sub-Saharan Africa\u0026quot; held in Nairobi, February 1997. \u003cem\u003eAgriculture, ecosystems and environment, 71\u003c/em\u003e(1/3).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eSmaling, E., Stoorvogel, J., \u0026amp;Windmeijer, P. 1993. Calculating soil nutrient balances in Africa at different scales. \u003cem\u003eFertilizer research, 35\u003c/em\u003e(3), 237-250.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eStoorvogel, J. J., \u0026amp; Smaling, E. M. A. 1990. Assessment of soil nutrient depletion in Sub-Saharan Africa: 1983-2000. Vol. 2: Nutrient balances per crop and per land use systems (0924-3062).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eVan Beek, C. L., Elias, E., Yihenew, G. S., Heesmans, H., Tsegaye, A., Feyisa, H., ... \u0026amp;Mengist, S. (2016). Soil nutrient balances under diverse agro-ecological settings in Ethiopia.\u0026nbsp;\u003cem\u003eNutrientCycling in Agroecosystems\u003c/em\u003e, \u003cem\u003e106\u003c/em\u003e(3), 257-274.\u003c/li\u003e\n \u003cli\u003eVan Beek, C., Brouwer, L., \u0026amp; Oenema, O. 2003. The use of farm gate balances and soil surface balances as estimator for nitrogen leaching to surface water. \u003cem\u003eNutrientCycling in Agroecosystems, 67\u003c/em\u003e(3), 233-244.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eVan Reeuwijk, L. 1992. Procedures for soil analysis. ISRIC, Wageningen, the Netherlands. \u003cem\u003eProcedures for soil analysis. 3rd ed. ISRIC, Wageningen, the Netherlands\u003c/em\u003e. \u003cem\u003e\u003c/em\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Nutrient input, Nutrient output, Nutrient balance, Lake Tana basin","lastPublishedDoi":"10.21203/rs.3.rs-3893338/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3893338/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003eNutrient balance analysis provides essential information concerning the current nutrient status of the soils and used to take appropriate nutrient replenishment practices. Nutrient flows were analyzed in Enqulal watershed of Dera district, Northwestern Ethiopia in the cropping season of 2018. Direct measurement and empirical formulas were used to identifying and measuring major inputs and outputs of NPK from different land uses within the catchments. Four nutrient inputs (Mineral fertilizer, Organic fertilizer, Atmospheric deposition and Nitrogen fixation) and five nutrient outputs (Crop yield, Crop residue, Gaseous lose, Leaching and Soil erosion) leaving the catchment were directly measured to calculate the partial and full nutrient balances. The results indicated that with the exception of phosphorus, teff cropland had negative partial N and K balances. The results also showed that the partial nutrient balances in wheat cropland were observed positive only for nitrogen. The full nutrient balances for the major cropland (wheat and teff) were found to be -20.9 kg , -0.7 kg ,\u0026nbsp; -37.87 kg ha\u003c/em\u003e\u003csup\u003e\u003cem\u003e-1\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e yr\u003c/em\u003e\u003csup\u003e\u003cem\u003e-1\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e\u0026nbsp; and -61.4 kg ,+11 kg, and -26.7 kg \u0026nbsp;ha\u003c/em\u003e\u003csup\u003e\u003cem\u003e-1\u003c/em\u003e\u003c/sup\u003e\u003cem\u003e yr\u003c/em\u003e\u003csup\u003e\u003cem\u003e-1\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eof N, P and K respectively. Generally, negative N and K full balances were found in this study for all land use/land cover. Therefore, the negative nutrient balances observed in cultivated land and other land uses indicated nutrient depletion which leads to land degradation and reduced agricultural productivity. Finally, analysis of the overall finding on nutrient balance implies that there is a need to enhance nutrient management in order to improve productivity and agricultural sustainability.\u003c/em\u003e\u003c/p\u003e","manuscriptTitle":"Nutrient Balance in Small Catchments of the Upland Areas of the Gumara River, Northwestern Ethiopia","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-30 12:10:24","doi":"10.21203/rs.3.rs-3893338/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a708b455-b30c-4935-8401-8248a58aea48","owner":[],"postedDate":"January 30th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-01-31T07:44:22+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-30 12:10:24","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3893338","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3893338","identity":"rs-3893338","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}