绿肥还田结合减量施氮对玉米干物质积累分配及产量的影响

【目的】分析绿洲灌区玉米干物质积累分配特征及籽粒产量对绿肥还田结合减量施氮的响应,以期为该区域发展高产、高效玉米生产技术提供理论依据。【方法】田间试验于2020―2021年在甘肃河西绿洲灌区进行,研究绿肥还田结合不同的减氮比例（绿肥还田结合减量施氮0%,N100;绿肥还田结合减量施氮10%,N90;绿肥还田结合减量施氮20%,N80;绿肥还田结合减量施氮30%,N70;绿肥还田结合减量施氮40%,N60）对玉米干物质积累分配及产量的影响。【结果】拔节期后N80和N90处理地上干物质积累量显著高于N70和N60处理,至成熟期N80处理较N70和N60处理提高了13.3%—23.2%,N90处理较N70和N60处理提高了13.9%—23.7%,N100、N90、N80处理间无显著差异;N80处理较N70和N60处理玉米地上干物质最大增长速率和平均增长速率显著提高了9.5%—21.2%、13.0%—23.2%,N90处理较N70和N60处理显著提高了10.2%—21.8%、13.9%—23.7%,二者均有效延缓了吐丝期至灌浆期玉米地上干物质积累速率的降低,而且N80处理较N70和N60处理干...

Effects of Returning Green Manure to Field Combined with Reducing Nitrogen Application on the Dry Matter Accumulation,Distribution and Yield of Maize

【Objective】 In order to provide the theoretical basis for the development of high-yield and high-efficiency maize production technology in this area, the characteristics of dry matter accumulation and distribution and the response of grain yield to the return of green manure to the field combined with nitrogen reduction were analyzed in the oasis irrigation area. 【Method】 The field experiment was carried out in Hexi Oasis Irrigation Area, Gansu Province from 2020 to 2021. The combination of green manure returning to the field and different nitrogen reduction ratios (green manure combined with nitrogen reduction 0%, N100; green manure combined with nitrogen reduction 10%, N90; green manure combined with nitrogen reduction 20%, N80; green manure combined with nitrogen reduction 30%, N70; green manure combined with nitrogen reduction 40%, N60) on the distribution of dry matter accumulation in maize and impact on production. 【Result】 After the jointing stage, the aboveground dry matter accumulation under N80 and N90 treatments was significantly higher than that of N70 and N60 treatments. At the mature stage, the aboveground dry matter accumulation under N80 increased by 13.3%-23.2% compared with N70 and N60 treatments, and N90 was higher than N70 and N60 treatments. Compared with the N70 and N60 treatments, the maximum growth rate and average growth rate of the aboveground dry matter under N80 were significantly increased by 9.5%-21.2% and 13.0%-23.2%, respectively; N90 significantly increased by 10.2%-21.8% and 13.9%-23.7% compared with N70 and N60 treatments, both of which effectively delayed the decrease of aboveground dry matter accumulation rate of maize from silking stage to grain filling stage. Compared with N70 and N60, the maximum growth rate of dry matter under N80 treatment was 2.44 d and 2.77 d earlier than that under N70 and N60, respectively, and N90 was 1.92 d and 2.3 d earlier than the N70 and N60 treatments, respectively. N80 and N90 promoted the distribution of dry matter in the ears of maize, and effectively increased the contribution rate of dry matter transport before flowering to grain dry matter accumulation. At the same time, the post-flowering dry matter accumulation under N80 increased by 12.2% and 20.4% compared with N70 and N60 treatments, respectively. Compared with the N70 and N60 treatments, the post-flowering dry matter accumulation under N90 was increased by 12.4% and 20.5%, respectively, and the difference was significant. There was no significant difference in maize grain yield among N100, N90, and N80 treatments, but the maize grain yield under N80 increased by 16.8% and 27.4%, respectively. Compared with N70 and N60 treatments, the yield under N90 treatment increased by 17.4% and 27.9%, respectively, with significant differences. 【Conclusion】 The return of leguminous green manure to the field combined with 10% and 20% nitrogen reduction treatments increased the aboveground dry matter accumulation and accumulation rate of maize, promoted the distribution of dry matter in the ears at maturity, and improved the pre-flowering dry matter transport on grain dry matter. The cumulative contribution rate could be used as the recommended nitrogen application method for high maize yield in oasis irrigated areas.