Deterministic Parameters of Growth and Yield of Wheat (Triticum aestivum L.) as Influenced by Fractional Application of Nitrogen and Potassium

An experiment was conducted during the winter (rabi) seasons of 2020-21 and 2021-22 at Krishi Vigyan Kendra, Budgam- Shere Kashmir University of Agricultural Sciences and Technology, Kashmir, to evaluate the growth and yield variability of wheat as effected by split application of potassium (K) and nitrogen (N). The experiment was set up in a split-plot design replicated thrice with K splits as main plot factor and N splits as sub plot factor which resulted in 15 treatment combinations, viz. of K 30 kg/ha [K1: 100% as basal dose-(RFP); K2: 50% as basal dose + 50% at active tillering; K3: 25 % as basal dose + 75% at active tillering] and 5 treatments of N:120 kg/ha in split ratios of [N1 : 50% as basal + 25% at jointing + 25% at booting stage (RFP); N2:25% as basal dose + 75% at active tillering; N3 : 25% as basal dose +50% at active tillering + 25% at booting; N4 : 50% as basal + 50% at active tillering; N5 : 0% as basal + 75% at active tillering + 25% at booting]. The results revealed that growth parameters like dry matter accumulation, leaf area index, SPAD reading at various phenological stages and quality parameters like N content (%) of grain and straw, protein content of grain, yield and N use efficiency were significantly more with the application of K in two equal splits in the ratio of 50:50 as compared to the treatment where K was applied in one split as 100% basal dose. There was the non-significant effect of split application of K and N on days taken to different phenological stages. Increase in N content (%) of grain was 5.76 and 5.73% during the year 2020-21 and 2021-22, respectively. Average percent increase in grain yield, protein content of grain and N use efficiency (grain yield (kg)/kg N applied) with the application of K in two equal splits in the ratio of 50:50 during both the years was 12.46, 5.81 and 12.46% that was significantly higher as compared to recommended fertilizer application (K1).