Effect of Predominant Integrated Nutrient Management Practices on Soil Quality Indicators and Soil Quality Indices under Post Monsoon (Rabi) Sorghum (Sorghum Bicolor) in Rainfed Black Soils (Vertisols) of Western India

ABSTRACT

A long-term study was conducted to study the impact of integrated nutrient management on soil quality in post-monsoon sorghum (Sorghum bicolor) at Solapur in Maharashtra State in Western India under All India Coordinated Research Project for Dryland Agriculture. The experiment was laid out with ten Integrated Nutrient Management Treatments in a randomized block design with three replications. The results of the study indicated that among all the integrated nutrient management treatments practiced, the application of 25 kg nitrogen (N) ha⁻¹ through crop residue (CR) + 25 kg N ha⁻¹ (urea) showed the highest soil quality index of 2.36, which was at par with other treatments receiving farmyard manure (FYM) and crop residues along with urea. The relative order of performance of the integrated nutrient management treatments in influencing soil quality was: T₆: 25 kg N ha⁻¹ (CR) + 25 kg N ha⁻¹ (urea) (2.36) >T₅: 25 kg N ha⁻¹ (FYM) (2.31) > T₇: 25 kg N ha⁻¹ (FYM) +25 kg N ha⁻¹ (urea) (2.30) = T₈: 25 kg N ha⁻¹ (CR) +25 kg N ha⁻¹ (Leucaena loppings) (2.30) > T₁₀: 25 kg N ha⁻¹ (Leucaena loppings) +25 kg N ha⁻¹ (urea) (2.17) > T₄: 25 kg N ha⁻¹ (CR:crop residues) (2.16) > T₉: 25 kg N ha⁻¹ (Leucaena loppings) (2.15) > T₃: 50 kg N ha⁻¹ (urea) (2.10) > T₂: 25 kg N ha⁻¹ (urea) (1.99) > T_1: 0 kg N ha⁻¹ (control) (1.77). The results of the study also indicated that average percent contribution of each soil key indicator towards soil quality indices was: pH (3.97%), EC (1.94%), organic carbon (18.6%), available P (2.80%), available K (6.57%), exchangeable Ca (7.02%), available S (3.45%), Available Zn (17.9%), dehydrogenase (DHA) (16.2%), microbial biomass carbon (MBC) (18.5%) and mean weight diameter (MWD) (3.14%). Thus, the results of the present study will be highly useful to the land managers in planning effective management of soil quality.

KEYWORDS:

• Integrated nutrient management (INM)
• principal component analysis (PCA)
• soil quality index (SQI)
• soil quality indicators
• Vertisols

Acknowledgments

The first author is thankful to Indian Council of Agricultural Research (ICAR) New Delhi for financially supporting this study under National Fellowship Programme on Soil Quality Assessment. The first author is also thankful to the present and former Directors of CRIDA, project coordinators of AICRPDA and scientists and staff of Solapur center for facilitating the study.