关键词: 双季稻, 湘南, 氮肥运筹, 产量, 抗倒伏

Abstract:

To explore the effects of different nitrogen fertilizer management modes on yield and lodging resistance of double-cropping hybrid rice in southern Hunan, field experiments were conducted with early rice varieties Luliangyou 996 and Zhuliangyou 819 and late rice varieties H you 518 and Shengtaiyou 018 as materials for comparative study of the effects of three proportion of basal and tiller fertilizer, panicle fertilizer, and grain fertilizer (N1: 7:2:1, N2: 6:3:1, and N3: 5:4:1) on yield and lodging resistance of double-cropping rice in Hengyang county, Hunan province, in 2019-2020. The results showed that nitrogen management mode had a significant effects on the yield of double-cropping rice. The N2 treatment had the best coordination effects on the yield components and the yield was the highest. Under the condition of 50%-60% basal and tiller fertilizer ratio, all varieties had higher bending resistance and lower lodging index but individual varieties showed inter-annual differences. Compared with N1, N2 and N3 treatments had lower plant height, lower center of gravity, thicker stem wall, shorter internode, and higher internode fullness and there was no significant difference between N2 and N3 treatments. Correlation analysis showed that the key to improve lodging resistance was to reduce plant height, the height of the center of gravity, and fresh weight of single stem and to improve stem diameter and fullness of the 4th internode from the top. Comprehensively considering the lodging index and yield characters of different varieties, 6:3:1 treatment with ratio of basal and tiller fertilizer, panicle fertilizer, and grain fertilizer could better coordinate the yield characters and lodging resistance of rice to achieve the goal of high yield and lodging resistance.

Key words: Double-cropping rice, Southern Hunan, Nitrogen fertilizer management, Yield, Lodging resistance