Effect of rice-establishment methods and nutrient management on productivity, profitability and soil health under rice (Oryza sativa)–groundnut (Arachis hypogaea) cropping system

Abstract

A field experiment was conducted during the rainy (kharif) and winter (rabi) seasons of 2019–20 and 2020–21 at the Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, to study the effect of different riceestablishment methods and nutrient management on yield, economics and soil properties in rice (Oryza sativa L.)– groundnut (Arachis hypogaea L.) cropping system. The experiment was laid out in a split-plot design with 3 replications. Six treatment combinations, comprising of 2 rice-establishment methods, viz. direct-seeded rice (DSR) and transplanted rice (TPR) and 3 levels of nutrient-management practices, viz. inorganic-100% soil test-based fertilizers (STBF), organic-dhaincha [Sesbania aculeata (Wild.) Pers.] green manuring +1/3rd soil test-based nitrogen (STBN) through vermicompost @2 t/ha + 1/3rd STBN through neem oil-cake @ 0.87 t/ha and integrated nutrient management (INM), viz. green-manuring + 50% STBN (inorganic @ 50.0 kg N/ha) + 100% P2 O5 + 100% K2 O, in rice during kharif were allotted to the main-plots. Three nutrient-management practices to groundnut during rabi, viz. 75% STBF, 100% STBF and 75% STBN (inorganic) + 25% STBN through FYM @ 1.63 t/ha + 0.2 lime requirement @ 0.38 t lime/ha + biofertilizers (Rhizobium + phosphate-solubilizing bacteria) + 100% P2 O5 + 100% K2 O, were allotted to the sub-plots. Transplanting of rice (TPR) increased the yield parameters of rice, resulting in 3.3% higher grain yield (5.65 t/ha) than direct seeding of rice. The INM improved the yield parameters of rice, resulting in 13.3 and 15.2% increase in grain yield over sole inorganic and organic practice, respectively. Carryover effect of the DSR on succeeding groundnut crop improved the yield attributes and resulted in 15.8% higher pod yield (2.49 t/ha) than the groundnut crop grown after TPR. Residual effect of organic nutrient management in rice crop enhanced the yield parameters of succeeding groundnut, resulting in 4.2 and 16.5% higher pod yield than the groundnut grown after INM and inorganic practice in rice, respectively. The INM practice in groundnut increased its yield parameters, resulting in 11.4 and 18.1% higher pod yield over 100% and 75% STBF, respectively. The DSR enhanced the system yield (12.51 t REY/ha) of rice-groundnut cropping system by 6.8% over TPR. The INM practice in rice crop enhanced system yield by 12.6 and 4.2% over inorganic and organic practice, respectively. Similarly, INM to groundnut crop resulted in 7.4 and 11.2% higher system yield than 100% and 75% STBF, respectively. The DSR, INM practice in rice and INM practice in groundnut crop fetched higher gross returns (`240.4 ×103 /ha, 245.5 ×103 /ha and 247.0 ×103 /ha), net returns (`97.2 ×103 /ha, 108.9 ×103 /ha and 92.7 ×103 /ha), benefit: cost ratio (1.71, 1.80 and 1.62) and system profitability (`207.9, 298.5 and 254.1/ha/day). Organic management under DSR and INM in groundnut improved the physico-chemical and biological properties of soil.