Abstract
Potassium (K) and magnesium (Mg) are essential plant macronutrients responsible for mitigation of biotic and abiotic stresses as well as enhancement in yield of maize. In rainfed maize, low productivity due to imbalanced use of fertilizers, erratic rainfall and periodic dry spells are major constraints. Hence, a field experiment was conducted in rainy season during 2015, 2016 and 2017 on an Inceptisol to optimize the levels of K and Mg in rainfed maize. The experiment consisted of four levels of K; control, K @20 kg ha−1, K@30 kg ha−1 and K 40 kg ha−1 and four levels of Mg; control, Mg@15 kg ha−1, Mg@30 kg ha−1, and Mg@45 kg ha−1. Application of K and Mg improved leaf area Index, chlorophyll content and relative water content in maize. Yield attributes of maize also improved significantly with application of K and Mg over control. Highest grain yield (3205 and 3169 kg ha−1) was recorded with the application of 40 kg K ha−1and 45 kg Mg ha−1, respectively which was at par with 30 kg K ha−1 (3103 kg ha−1) and 30 kg Mg ha−1 (3106 kg ha−1), respectively. The highest net returns (US $347 ha−1) and BC ratio (1.72) was recorded with 40 kg K ha−1 while application of 30 kg Mg ha−1 recorded highest net returns (US $332 ha−1) and BC ratio (1.71). Application of 30 kg K ha−1 and 30 kg Mg ha−1 was found to be optimum to improve growth, yield and nutrient uptake in rainfed maize.
Acknowledgments
We are extremely grateful to Indian Council of Agricultural Research-Central Research Institute for Dryland Agriculture, Director CRIDA and Project Coordinator.
Disclosure statement
No potential conflict of interest was reported by the authors