Post-submergence Nitrogen Fertilizer Management for Enhancing Rainfed Lowland Rice Productivity in Eastern India

Abstract

Flashflood in rainfed lowlands seriously affect rice crop establishment and cause severe yield losses. Survival of new flood tolerant rice varieties (Swarna-Sub1, Samba Mahsuri-Sub1, IR64-Sub1, etc.) developed through introgressing the submergence tolerance gene SUB1into mega rice varieties of South Asia is substantially higher than that of non-Sub1 varieties under flooding stress. This has been consistently reflected in a yield advantage of 1 to 3 t ha-1. Submergence tolerance and productivity of these Sub1 varieties can be further enhanced through adoption of appropriate crop and nutrient management practices. Postflood nitrogen application plays an important role in helping rice plants to resume quick growth after flood water recession. On station experiments conducted during the wet seasons (Kharif) of 2011 and 2012 at the college of agriculture, Chiplima, Sambalpur, Odisha, to study the effect of 3 post-flood nitrogen doses (N 1 : 10 kg ha-1 ; N 2 : 20 kg ha-1 ; N 3 : 30 kg ha-1) and 3 application times (% plants started showing at least one green leaf after de-submergence) viz. T 1 : 10-15%; T 2 : 30-35% and T 3 : 65-70% on survival, growth and yield performance of the rice variety Swarna-Sub1. Treatments N 3 (91.4%) and T 2 (96.3%) produced significantly higher survival than other treatments. Additional N increased the yield attributes and finally grain yield. Mean maximum grain yield was recorded with N 3 (3485 kg ha-1) and T 2 (3623 kg ha-1). When the additional N dose was applied earlier (T 1) or late (T 3), the average yield reduction was 19 and 12%, respectively, compared to T 2 .

Phenology, growth and productivity of rice (Oryza sativa l.) under reduced sunlight intensity and foliar nitrogen application

“…Higher grain yield with foliar application of nitrogen might be due to higher values of growth parameter which might have resulted in higher capture of solar energy and hence led to enhanced values of yield attributing characters, that ultimately resulted in higher grain yield. Similar results were also reported by Behera et al (2019).…”

“…Among nitrogen levels, N B resulted in maximum number of tillers m -2 and it was statistically at par with those under N M and N MA at both the locations (Table 4). Behera et al (2019) also reported higher number of tillers hill -1 under higher doses of nitrogen as compared to lower doses.…”

“…Among nitrogen levels, N B resulted in maximum plant height and it was statistically at par with all other foliar nitrogen application treatments and was significantly more than control, at both the locations (Table 4). Behera et al (2019) also reported higher plant height under higher doses of nitrogen application.…”