Ecological Adaptability And Nitrogen Utilization Efficiency In Super Hybrid Rice

Seven hybrid rice combinations, Luliangyou996, Fengyuanyou299, Cliangyou4488, Longliangyou187, Zhunliangyou893, Y58S/599 and Weiyou46 (control), were used as materials, and three experiments on variety compare, effect of nitrogen fertilizer planning (6:2:1:1 and 4:2:3:1) on yield and nitrogen utilization efficiency of super early rice and effect of nitrogen application on yield and nitrogen utilization efficiency of super late rice were conducted to investigate the ecological adaptability and nitrogen utilization efficiency of super hybrid rice. The main results were as follows:(1) Among the tested late rice combintions, yield superiority of Fengyuanyou299 and Cliangyou4488 was clear and their yields situated the first and second position in Changsha and Chenzhou. The main characteristics of Fengyuanyou299 were bigger panicle and higher 1000-grain weight, weaker tillering capability, higher ear-bearing tiller rate and less effective panicles, and its growth duration was 5 d shorter than that of Weiyou46 (control) in Changsha region while they were equal in Chenzhou region. The main characteristics of Cliangyou4488 were bigger panicle and higher 1000-grain weight, stronger tillering capability, lower ear-bearing tiller rate and less effective panicles, and its growth duration was 2-3 d longer than that of Weiyou46 (control) in Changsha and Chenzhou. In this study, planting combinations with bigger panicle and higher 1000-grain weight was apt to higher gain yield.(2) Nitrogen application and lingering movement of nitrogen fertilizer (RMNF) had significant effect on yield increasing, and planting by wide-narrow-row (PWNR) had effect on yield increasing at some extent. Yield of super rice was highest when nitrogen application, RMNF and PWNR were applied at the same time. As for effect on yield increase of single cultivation measure, nitrogen application was best, and the next was RMNF, and the third was PWNR.(3) Cultivation measures affected nitrogen utilization efficiency of super rice. Nitrogen accumulation in shoot was increased significantly, while nitrogen physiological efficiency (NPE), nitrogen harvest index (NHI) and nitrogen utilization efficiency (NUTE) were decreased by nitrogen application. Nitrogen accumulation, nitrogen use efficiency (NUE) and nitrogen fertilizer efficiency (NFE) in 4:2:3:1 treatment were significantly higher than those in 6:2:1:1 treatment. Compared to equal-row treatment, nitrogen accumulation, NUE and nitrogen uptake efficiency (NUPE) were increased significantly while NHI and NUTE were decreased significantly in PWNR treatment.(4) Cultivation measures affected shape of plant and leaf of super rice. Length and width of functional leaves were signifieantly inreased by nitrogen application, and they were affected by nitrogen fertilizer planning mode and planting mode at some extent. Leaf angles of functional leaves were signifieantly increased by nitrogen application, and they were increased by RMNF at the same time. Nitrogen application and PWNR could heighten the diameter of stem and then heighten the lodging resistance, and the effect of nitrogen application was better than that of PWNR.(5) Super hybrid rice had clear yield superiority, at the same time, nitrogen accumulation, NUPE, NHI, NFE, NUTE and NUE of super rice were signifieantly higher than those of common hybrid rice. Application of super hybrid rice in production can not only increase yield of food but also heighten the utilization efficiency of resources and reduce the environment pollution induced by nitrogen fertilizer loss.