Plant residue quality index and ecological potential approach for selective reincorporation of crop residues in soil.

Reintegration of agricultural residue into the soil is a sustainable approach for replenishment of soil nutrients. Plant physiology determines the quality of residue produced by a crop and its quality governs the process of decomposition in the soil. The present study attempts to establish formulated approach to select quality crop residues for re-usage in soil. Four major crops, rice, wheat, maize and sugarcane were selected to analyse their quality and quantitative potential to generate a quality index. Residue production ratio (RPR), agricultural ecological potential (AEP) and, gross residue potential (GRP) values were determined to correlate their decomposition pattern with nutrient release rate. The calculated gross residue potential showed the availability of residue generated by crop was highest in wheat. Agricultural ecological potential further implied that 48% of wheat and maize crop residue should be left on the field for maintaining ecological services. The results are studied in coherence to explain the ecological importance of retaining crop residues in the field. The chemical parameters integrated as plant residue quality index (PRQI) further confirms the high nutrient value of wheat and rice crop residues correlated with their higher decomposition rate. The present study implies that decomposition rate of crop residues can decide their retain value depending on nutrient release rate. This would facilitate in establishing the relationship between qualities of decomposing residue requirements with crop growth of a particular species.