Genotype variation in grain yield response to basal N fertilizer supply among different rice cultivars

Abstract

Considering the great amount of basal N fertilizer but lower uptake ability at rice seedling, it was essential to increase the N use efficiency of basal fertilizer and reduce N pollution. So, a field experiment was conducted at Wuxi, China, under non-basal N and basal N fertilizer conditions, to identify the variation of grain yield response to basal fertilizer among 199 rice varieties with different genetic background, and finally choose the suitable rice varieties for us to increase basal N fertilizer efficiency and reduce N fertilizer pollution. The results show that highly significant genotype differences for grain yield and almost yield parameters existed in 199 rice varieties, and there were also great differences for agronomic N use efficiency (ANUE) and apparent recovery of applied basal N fertilizer (AR) among 199 rice varieties. Little response rice varieties HJY, 80-4, L454, SXJ, Daesong, WNZ and DXW2, and great response rice varieties NJ1X, HC106, QYDD, YTDBM, YJ2H, 4020 and 4024 were also screened in this study. Our results also show that the effects of basal fertilizer were mainly reflected on the early period of rice growth but not on the grain yield. This study identified genotype variation in grain yield response to basal N fertilizer supply and great ANUE and AY differences among the 199 rice cultivars, and also explored the reasons for these phenomena, which would provide us good information in increasing basal fertilizer efficiency and reducing N pollution. Key words: Basal fertilizer, rice varieties, response, nitrogen, grain yield.