Saikia, M.Konwar, Milon Jyoti2021-01-122021-01-122020-10https://krishikosh.egranth.ac.in/handle/1/5810159942A field experiment entitled “Real time nitrogen application in winter rice under different crop establishment techniques” was carried out in the year 2017 and 2018 in the Instructional-Cum-Research (ICR) farm, Assam Agricultural University, Jorhat to study the relative performance of winter rice varieties with LCC- based N application under different crop establishment techniques. The experiment was comprising of 45 treatment combinations with three varieties viz., V1: Ranjit, V2: Bahadur, V3: Gitesh; three crop establishment techniques viz., M1: Transplanting, M2: System of Rice Intensification, M3: Direct seeding by drum seeder and five nitrogen application techniques viz., N0 : Recommended dose of N (60 kg ha-1); N1 : 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 2;N2 : 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 3; N3 : 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 4; N4 : 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5, laid out in a split-plot (split-split) design with varieties in the main plots, crop establishment techniques in the sub-plots and nitrogen application techniques in the sub-sub plots and were replicated thrice.The soil of the experimental site was sandy loam, acidic in reaction, medium in organic carbon and available N, low in available P2O5 and K2O. Among the different growth and physiological parameters viz., plant height, tillers m-2, dry matter accumulation, CGR, RGR and NAR, the highest values recorded in the variety Ranjit followed by Bahadur and Gitesh. Similarly, in case of crop establishment techniques and nitrogen application techniques, SRI and 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 recorded the highest values in different growth and physiological parameters viz., plant height, tillers m-2, dry matter accumulation, CGR, RGR, NAR during 2017 and 2018, respectively. Root volume was also significantly affected by different varieties and was found to be the highest in Ranjit followed by Bahadur and Gitesh. Similarly, in case of crop establishment techniques, the root volume was recorded highest in SRI method followed by transplanting and direct seeding by drum seeder whereas the root volume was found to be highest in application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 as compared to recommended dose of nitrogenin different nitrogen application techniques. The results from the pooled data revealed that the variety Ranjit recorded significantly the highest yield attributing characters and grain as well as straw yields of 47.22 q ha-1 and 87.12 q ha-1 during 2017 and 2018. In case of methods of crop establishment, SRI recorded significantly higher grain and straw yields of 46.54 q ha-1 7 and 85.86 q ha-1 as compared to sowing by drum seeder. Application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 recorded significantly the highest grain as well as straw yields of 53.65 q ha-1 and 94.48 q ha-1, respectively as compared to other treatments. Pooled data of the treatment combinations showed that application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 with Ranjit establishing with SRI method registered significantly higher grain and straw yields over other treatment combinations. The highest grain and straw yields of rice from the pooled data was recorded with the application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 in Ranjit when SRI method of crop establishment was followed. The uptake of N, P, K and total uptake had been significantly affected by different varietal treatments. The highest uptake was found in case of Ranjit followed by Bahadur and Gitesh. In different crop establishment techniques N, P, K and total uptake was found to be the highest in case of SRI method followed by transplanting and direct seeding by drum seeder. Highest uptake was also found in application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 in comparison to other treatments.Results from the apparent nitrogen balance sheet indicated that the highest net gain in available N in soil was recorded in application of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 in Ranjit when SRI method was followed during 2017 and 2018, respectively,as compared to other treatment combinations. In case of economics, the higher net returns and B:C ratio (1.65 and 1.62) was recorded under treatment combinations of 30 kg N as basal + 15 kg ha-1 N when LCC ≤ 5 with Ranjit and drum seeder method of crop establishment in 2017 and 2018, respectively.EnglishThesis