EFFECT OF POTASSIUM AND SPLIT APPLICATION OF NITROGEN ON YIELD ATTRIBUTES AND YIELD OF SOYBEAN [GLYCINE MAX (L.) MERRILL]

A field experiment under varied nutrient management and different time of N application was conducted during  kharif  2007 and 2008 at Punjab Agricultural University, Ludhianato study the effect of N application at different growth stages and potassium application on growth and yield of soybean.  The experiment included fourteen treatments comprising of three levels of N (0, 30 and 45 kg/ha) along with two levels of potassium (0 and 30 kg K2O/ha) tested at two different growth stages viz. pre-flowering and pod filling in randomized block design with four replications. Higher seed yield (25.1 q ha-1  and 24.8 q ha-1 during 2007 and 2008 respectively) was obtained with treatment T8 (20 kg N ha-1 at sowing + 10 kg N ha-1 at pod filling + 30 kg K2O ha-1 at sowing) indicating the beneficial effect of split application of nitrogen along with potassium. The increase in the growth and yield attributes resulted in the higher seed yield of soybean, which was significantly higher than all other treatments.  Application of nitrogen in two splits i.e. at pre-flowering and pod filling stage with or without potassium had beneficial effect on growth and yield of soybean as compared with single dose applied at either of the stages.