Influence of Tillage and Nutrient Sources on Yield Sustainability and Soil Quality under Sorghum– Mung Bean System in Rainfed Semi-arid Tropics

Abstract

The crop production in rainfed semi-arid tropical (SAT) Alfisols is constrained by low soil organic matter, poor soil fertility, soil structural infirmities, and scarce moisture availability. To offset some of these constraints, a long-term study of tillage [conventional (CT) and reduced (RT)] and conjunctive nutrient-use treatments was conducted in SAT Alfisol at Hyderabad, India, under sorghum–mung bean system. The order of performance of the treatments in increasing the sorghum yield was 2 Mg gliricidia loppings + 20 kg nitrogen (N) through urea (T4) (93.2%) . 4Mg compost + 20 kg N through urea (T3) (88.7%) . 40 kg N through urea (T2) (88.5%) . 4 Mg compost + 2 Mg gliricidia loppings (T5) (82.2%). In the case of mung bean, where half as much N was applied as was to the sorghum, the order of performance of the treatments in increasing the grain yields was T3 (63.6%) .T5 (60.3%) .T4 (58.0%) .T2 (49.6%). Tillage significantly influenced the hydraulic conductivity only, whereas the conjunctive nutrient-use treatments significantly influenced the predominant physical, chemical, and biological soil-quality parameters. Among the conjunctive nutrient-use treatments, T5 was found to be superior in influencing the majority of the soil-quality parameters and increased the organic carbon by 21.6%, available N by 24.5%, dehydrogenase activity by 56.1%, microbial biomass carbon by 38.8%, labile carbon by 20.3%, and microbial biomass nitrogen by 38.8% over the unamended control and proved superior most in improving soil quality.