Long-Term Effects of Soil and Nutrient Management Practices on Soil Properties and Additive Soil Quality Indices in SAT Alfisols

摘要

A long term experiment was conducted for 11 years to study the effects of soil and nutrient management practices soil fertility and additive soil quality indices in rainfed Alfisol, at Hyderabad, India. The treatments were comprised of conventional tillage (CT) and minimum tillage (MT) as main factors, sorghum stover (dry) @ 2 t/ha (SS), fresh gliricidia loppings @ 2 t/ha(GL and no residue (NR) application on surtace as sub-treatments and N levels @ 0, 30, 60 and 90 kg N/ ha as sub- sub treatmentsiicastor-sorghum yearly rotation. The results indicated that after 11 years, MT significantly improved organic carbon (OC), available N, available K. exchangeable Mg. ailable S, microbial biomass carbon (MBC), dehydrogenase activity (DHA), labile carbon(LC bulk density (BD) and mean veight diameter (MWD) of soil aggregates. Application of sorghum residue and gliricidia loppings showed significant increase in OC' by 6.28% and 3.7%, respectively over NR. Statistical regression functions indicated that parameters viz., MliC. LC. MWD. OC, S, Fe and DHA influenced by long term soil management practices significantly influenced the crop yield. The physical (PSQI). physico-chemical (PCSQI), chemical (CSQl), biological (BSQI) and additive SQIs (ASQI)wete significantly influenced by management treatments. On an average, the percent contribution of these component soil quality indices towards ASQI was in the order of BSQI (32.I%)>CSQ1 (26.1%) > PSQI (25.7%) > PCSQI (16.2%). Crop yields were significantly correlated with these indices and thus emphasized their importance in increasing the productivity in these semi arid Alfisol soils.