Effect of Integrated K Management on Productivity and Nutrient Use Efficiency of Maize-Wheat Cropping System

Abstract

A field experiment was conducted during the rainy (June - October) and winter (November – March) seasons for two years during 2010-2012 at research farm of ICAR - Indian Agricultural Research Institute, New Delhi, India. The experiment was laid out in a randomized block design consisting of seven treatments and three replication. Results revealed the integrated application of 90 kg K ha-1 supplemented through muriate of potash (MOP) @ 60 kg K and farmyard manure (FYM) @ 30 kg K resulted in highest grain yield of 4.93 t ha-1 and biological yield of 11.71 t ha-1 in maize. Similarly, highest grain yield of 5.44 t ha-1 and biological yield of 14.03 t ha-1 were observed in treatment applied with integrated dose of K @ 90 kg K ha-1 supplemented through MOP and FYM in wheat crop. The highest uptake of K was observed under treatment applied through 30 kg K through MOP + 30 kg K through FYM in both cropping cycles. Nutrient use efficiency of N, P and K increased by K application. In soil, decline was observed in different fractions of K irrespective of different applied K treatments. All the treatments where K was added showed a negative balance of K availability in soil. Application of 60 kg K ha-1 through MOP in both the season showed minimum negative K balance (-281.3 kg ha-1). Integrated K application @ 90 Kg K ha-1 resulted in highest exchangeable and nonexchangeable K in the soil for both seasons. To achieve a sustained yield level, nutrient use efficiency and soil fertility integrated K application @ 60 kg K ha-1 for the rainy season in maize and a dose of 60 kg K ha-1 through MOP alone in the winter season for wheat crop may be recommended.