Exploring Soil Characteristics and Agricultural Sustainability in Western Anatolia's Colluvial Deposits

Colluvial soils play a vital role in the soil composition of western Anatolia, Turkiye, originating from the accumulation of eroded materials at the base of slopes and in closed depressions. It is claimed that colluvial lands are generally unsuitable for agriculture due to slope, shallow soil and nutritional deficiency. However, due to increasing population pressure, agriculture in colluvial lands, which are considered marginal, becomes a necessity as normal agricultural areas are limited in agricultural production. The research hypothesis posits that despite the slope, shallowness of the soil and nutritional deficiency of colluvial lands, if the appropriate plant is selected and the climate and geographical conditions are optimum, strategically important agriculture can be carried out. This study aims to characterize the soil properties of colluvial in western Anatolia, specifically focusing on their agricultural potential for olive, fig, and grape cultivation. Geological origins and topographic features of colluvial were initially assessed, followed by the collection of soil samples from both natural and agricultural areas. Comprehensive analyses were conducted on both colluvial materials and the corresponding soil samples. The findings were statistically evaluated using principal component analysis, with a subsequent discussion on the agricultural sustainability of the soils for the selected plants. The results indicate that the colluvial lands in the study area are generally unsuitable for agriculture due to factors such as slope, erosion risk, shallow soil depth, low soil organic matter, and limited nutritional capacity. However, under favorable climatic conditions, certain specialty crops, such as olives and figs, can thrive, offering economic benefits to the local population. Despite the overall limitations for traditional agriculture, the cultivation of these specific plants contributes to both the economic well-being of the region and the overall sustainability of agriculture in the area.