Balanced fertilization in rice (Oryza sativa)-groundnut (Arachis hypogaea) cropping system

A field experiment was conducted in farmers’ field of Angul district under mid-central table land zone of Odisha by involving 48 farmers during 2013–15, to study the response of rice (Oryza sativa L.)-groundnut (Arachis hypogaea L.) cropping system to balanced nutrient application. The highest system rice-equivalent yield (REY) (10.78 t/ha) was recorded with the recommended doses of nitrogen, phosphorus and potassium (N, P and K @ 80, 17.5 and 33 kg) + 25 kg ZnSO₄/ha to rice and recommended doses of N, P and K @ (40, 17.5 and 33 kg/ha) + 250 kg CaSO₄/ha to groundnut followed by recommended NPK alone without ZnSO₄/CaSO₄ (10.36 t/ha). The average increase in system REY of these 2 treatments was 73 and 66% over the control (6.23 t/ha) and 25 and 20% over the farmers’ practice (8.63 t/ha). Agronomic efficiency (AE) of N, P and K was 19.8, 29.0 and 17.2 kg REY/kg applied nutrient for rice-groundnut system. The agronomic efficiency of N increased by 49, 55 and 108% in rice- groundnut system by applying the recommended quantity of N with recommended quantity of P, K and PK, respectively, instead of N alone. The AE of P and K increased by 40 and 34% in rice-groundnut system when the recommended quantity of P or K was applied with recommended quantity of NK or NP instead of with N alone. Application of NPK + ZnSO₄ to rice and NPK + CaSO₄ to succeeding groundnut recorded the highest system net returns (63,123/ha) followed by application of recommended NPK to both the crops(60,509/ha). These 2 treatments also recorded higher nutrient uptake due to the high biomass production with application of balanced nutrients.