Yield, nutrient uptake and economics of Indian mustard (Brassica juncea) as affected by split and foliar application of potassium

Potassium management in Indian mustard

Abstract

A field experiment was carried out during winter (rabi) season 2021-22 at the ICAR-Indian Agricultural Research Institute in New Delhi to find out the effect of potassium management on yields, nutrient uptake and economics of Indian mustard. The soil of the experimental site was sandy loam in texture with pH of 7.1, organic carbon (0.53%), available nitrogen (208 kg/ ha), available phosphorus (13 kg/ ha) and available potassium (222 kg/ ha). There were eight treatments combinations of different doses, methods and time of potassium application i.e. No K = 0 kg K/ha; Basal 100% MOP (muriate of potash) = 33.2 kg K/ha; 100% MOP as basal = 33.2 kg K/ha; 2 Foliar sprays of KNO3 at branching and before flowering = 8.8 kg K/ha; 50% MOP as basal + 50% MOP as top dressing at branching = 33.2 kg K/ha;  50% MOP as basal + 2 foliar sprays of KNO3 at branching and before flowering = 25.4 kg K/ha; 75% MOP as basal + 25% MOP as top dressing at branching = 33.2 kg K/ha; 75% MOP as basal + one foliar spray of KNO3 at branching = 25.4 kg K/ha;  75% MOP as basal + one foliar spray of KNO3 at before flowering =  25.4 kg K/ha. Grain yield, straw yield, harvest index, NPK uptake was obtained significantly higher under the treatment, 75% MOP as basal + one foliar spray of KNO₃ before flowering, over 50% MOP as basal + 2 foliar sprays of KNO3 at branching and before flowering, 50% MOP as basal + 50% MOP as top dressing at branching, 2 foliar spray of KNO3 at branching and before flowering, 100% MOP as basal and control. However, the treatment i.e. 75% MOP as basal + one foliar spray of KNO3 before flowering remained significantly at par with 75% MOP as basal + one foliar spray of KNO3 at branching and 75% MOP as basal + 25% MOP as top dressing at branching. Higher net return and benefit: cost ratio was observed in the treatment of 75% MOP as basal + one foliar spray of KNO₃ before flowering was recorded which remained at par with most of the treatments except control, 100% MOP as basal), 2 foliar sprays of KNO₃ at branching and before flowering, 50% MOP as basal + 50% MOP as top dressing at branching, and 50% MOP as basal + 2 foliar sprays of KNO₃ at branching and before flowering.