Sowing time and nutrient management for productivity enhancement of upland rice(Oryza sativa L.)

Abstract

The field experiment entitled “Sowing time and nutrient management for productivity enhancement of upland rice (Oryza sativa L.)” was conducted during Kharif 2019 at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram with the objective to study the influence of different levels of N and K, their ratios and time of sowing on growth and yield of upland rice and to work out the economics of cultivation. The variety used for the study was Aiswarya (PTB 52). The experiment was laid out in factorial RBD consisting of 12 treatment combinations and 3 replications. The treatments comprised of 6 levels of N and K in 2:1 and 2:1.5 ratios (l1:60: 30 (control-1), l2: PGPR MIX- I : 6 kg + FYM 5 t ha-1 (control-2), l3 : 120: 60, l4 :120: 90, l5 : 140: 70 and l6 :140:105) and 2 time of sowing (s1: sowing one week after the commencement of SW monsoon, 2019 and s2: sowing two weeks after the commencement of SW monsoon, 2019). A uniform dose of P2O5 (30 kg ha-1) was applied to all the plots. The treatment l6 (140:105 kg ha-1 of NK at 2:1.5 ratio) resulted the tallest plants and highest DMP at 60 DAS and at harvest. The maximum number of tillers m-2 was produced in the treatment l6 (140:105 kg ha-1 of NK at 2:1.5 ratio). Regarding the time of sowing, s1 (sowing one week after the commencement of SW monsoon, 2019) produced the tallest plants, maximum DMP and number of tillers m-2. Growth characters were favoured in the treatment combination l6s1 (140:105 kg ha-1 of NK at 2:1.5 ratio and sowing one week after the commencement of SW monsoon, 2019). The yield attributes such as productive tillers m-2, length of panicle, grain weight panicle-1, number of spikelets panicle-1, percentage of filled grains, 1000 grain weight, grain and straw yields were significantly influenced by the treatments. The treatment l6 (140:105 kg ha-1 of NK at 2:1.5 ratio) resulted in the highest value. With respect to time of sowing, the treatment s1 (sowing one week after the commencement of SW monsoon, 2019) had the highest values for the above mentioned characters. The interaction effect differed significantly only for productive tillers m-2, number of spikelets panicle-1, grain and straw yields. The treatment combination l6s1 (140:105 kg ha-1 of NK at 2:1.5 ratio and sowing one week after the commencement of SW monsoon, 2019) showed the maximum values. The nutrient use efficiency was significantly influenced by the treatments. The maximum NUE was recorded by the treatment l2 (PGPR MIX 1 6 kg + FYM 5t ha-1). The treatment s1 (sowing one week after the commencement of SW monsoon, 2019) resulted in the highest NUE. Among the treatment combinations, l2s1 (PGPR MIX 1 6 kg + FYM 5 t ha-1and time of sowing one week after the commencement of SW monsoon, 2019) had the maximum NUE. The treatment l1 (60:30 kg ha-1 of NK at 2:1 ratio) had the maximum KUE. With respect to time of sowing, the treatment s1 (sowing one week after the commencement of SW monsoon, 2019) had the highest KUE. The treatment combination l1s1 (60:30 kg ha-1 of NK at 2:1 ratio and sowing one week after the commencement of SW monsoon, 2019) had the highest KUE. The results revealed that the treatment l6 (140:105 kg ha-1 of NK at 2:1.5 ratio) resulted in the maximum nutrient uptake. With regard to time of sowing, the treatment s1 (sowing one week after the commencement of SW monsoon, 2019) showed higher uptake of nutrients. The treatment combination l6s1 (140:105 kg ha-1 of NK at 2:1.5 ratio and time of sowing one week after the commencement of SW monsoon, 2019) resulted in the maximum uptake of nutrients. The protein content of grain was significantly influenced by the NK ratios. Among the treatments, l6 (140:105 kg ha-1 of NK at 2:1.5 ratio) indicated the maximum grain protein content. The economic analysis revealed that the treatment l6 (140:105 kg ha-1 of NK at 2:1.5 ratio), s1 (sowing one week after the commencement of SW monsoon, 2019) and the treatment combination l6s1 (140:105 kg ha-1 of NK at 2:1.5 ratio and sowing one week after the commencement of SW monsoon, 2019) fetched the maximum gross income, net income and BCR. From this study, it can be concluded that the application of 140 kg N and 105 kg K2O ha-1 (2:1.5 ratio) and sowing one week after the commencement of SW monsoon resulted in higher growth characters, yield attributes, yield, gross income and net income.