Influence of seedling age and different levels and methods of application of nutrients on yield, nutrient content and uptake of rice (Oryza sativa L.)

A field experiment was conducted during the rainy (kharif) season of 2016 and 2017 at Dapoli, Maharashtra, to study the influence of different age of seedling age, levels and methods of fertilizers application on growth, yield, nutrients content, uptake and economics in rice (Oryza sativa L.). The result revealed that the 20-day-old seedling resulted in significantly highest grain and straw yield (tonnes/ha) as compared to 30-day and 40-day old seedlings. Among different levels of fertilizer application, 125% recommended doses of fertilizer (RDF) resulted in significantly higher grain and straw yields followed by 100% RDF and 75% RDF in that descending order. Significantly higher value of grain and straw yields (tonnes/ha) were recorded in treatment split application of potassium with Zn, B and Cu spray (K4) followed by basal application of potassium with Zn, B and Cu spray (K3) which were at par and also significantly superior to all other treatments. The result also revealed that the 20 days old seedling showed the highest content of N (1.125, 1.126% in grain and 0.554, 0.56 % in straw), P (0.227 and 0.225% in grain and 0.114 and 0.112 % in straw), K (0.340 and 0.325 % in grain and 1.139 and 1.134 % in straw) and total uptake of N (137.09 and 130.31 kg/ha), P (27.85 and 25.26 kg/ha), K (131.94 and 122.07 kg/ha), Zn (361.99 and 321.78 g/ha), Cu (284.15 and 257.26 g/ha) and B (99.68 and 93.28 g/ha) as compared to 30 days and 40 days old seedling during both the years of study. While Zn contents (20.54 and 19.93 mg/kg in grain and 22.35 and 20.43 mg/kg in straw) were found to be significantly superior to 45 days old seedling and at par with 30 days old seedling during both the years. Among different levels of fertilizer application, the 125% RDF significantly increased content of N (1.143 and 1.145% in grain and 0.559 and 0.552% in straw), P (0.221 and 0.218% in grain and 0.112 and 0.109% in straw), K (0.319 and 0.318% in grain and 1.136 and 1.132% in straw) and total uptake of N (132.19 and 122.81 kg/ha ), P (25.97 and 23. 22 kg/ha ), K (123.74 and 114.03 Kg/ha), Zn (341.63 and 298.12 g/ha), Cu (267.83 and 237.51 g/ha) and B (93.84 and 86.39 g/ha), followed by 100% RDF and 75% RDF in that descending order during both years. The significantly higher value of N (1.115 and 1.117 %) and P (0.219 and 0.217) contents in grain and uptake of N (126.03 and 118.88 kg/ha), P (25.05 and 22.82 kg/ha), K (121.37 and 112.88 kg/ha), Zn (334.11 and 295.23 g/ha), Cu 260.70 and 233.89 g/ha) and B (91.84 and 85.70 g/ha) were recorded in treatment K4 (split application of potassium with Zn, B and Cu spray), followed by K3 (basal application of potassium with Zn, B and Cu spray) which were on par with each other and significantly superior to the remaining treatments. The contents of K, Zn, B and Cu in grain and straw were not influenced significantly as different methods of fertilizer application.