氮肥不同运筹模式对水稻生产及氮肥利用率的影响

Effects of Nitrogen Application Strategies on Production and Fertilizer-N Use Efficiency of Rice

氮肥是作物增产的重要因素。针对水稻氮肥用量过高,前期氮肥比例过大这一突出问题,本试验选取水稻"前肥后移、精确定量"施肥技术,对特定生态区水稻主栽品种的氮肥运筹进行研究与优化。研究氮肥后移对水稻碳氮物质积累、运转、分配及品质形成的影响,进一步明确不同氮肥运筹下水稻产量和品质形成的调控机制,以采取更有效的措施达到高产、优质的目的。结果表明,氮肥后移使分蘖期群体分蘖的发生受到一定程度的抑制,降低了拔节前植株的吸氮量。但在氮肥后移之后,拔节-抽穗阶段的植株吸氮量明显提高,每穗总粒数显著增加,在一定程度上表现出了增产的效果;氮肥后移的效果与氮肥施用量有关,在N15、N18和N21处理下,当氮肥运筹比例为5∶5时产量较高。综合多年的试验表现,江苏麦茬单季晚粳稻以N18处理下氮肥运筹比例为5∶5时效果最佳。

Nitrogen fertilizer is an important factor for crop production. The N application strategies named as former nitrogen moved backward （FNMB） were tested in three ecological regions to optimize the N application in rice. The dry matter accu- mulation and distribution, yield and quality were studied to understand the formation of yield and quality of rice under dif- ferent N application strategies. The result indicated that former nitrogen moved backward （FNMB） can inhibit tillering to some extent and reduce nitrogen uptake before jointing stage. But the yield can increase by the augment of total grains per ear and nitrogen uptake at the stage of jointing and booting, the effect of former nitrogen moved backward （FNMB） related to nitro- gen application amount, it can achieve higher yield when the ratio of nitrogen application was 5：5 under the treatment of N15, N18 and N21. According to test showing, the best result can be achieved when the ratio of nitrogen application strate- gie was 5：5 under the treatment of N18 in Jiangsu.