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%) > 4 Mg 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.

Keywords:

• Alfisols
• conventional and reduced tillage
• crop yield sustainability
• farm‐based organics
• soil fertility
• soil‐quality indicators

ACKNOWLEDGMENTS

The authors are thankful to the former director of CRIDA, Dr. H. P. Singh, who inspired and facilitated this theme of research, and the present director, Dr. Y. S. Ramakrishna, for providing the necessary support in conducting this research. The authors are also thankful to the officer‐in‐charge, Hayathnagar Research Farm, and Mr. Chandra Mohan Reddy, farm superintendent, for providing necessary facilities in the farm for conducting the field experiment and also to Mr. Arokia Swamy, technical officer, for providing technical help during the study period.