抚仙湖北部农田区不同施肥对水稻产量、氮素吸收及利用率的影响

针对抚仙湖北部农田区的蔬菜施肥过量导致土壤养分残余量大,会对后作水稻施肥造成影响的问题,采用田间小区开展不同施肥试验研究。结果表明,砂壤土和粘壤土在施氮量为150~360 kg/hm2范围内,水稻植株氮素积累量随着施氮量的增加而提高,而增加的氮素积累量主要表现在茎叶部位;穗肥施用氮肥可提高籽粒氮素积累量。水稻氮肥吸收利用率和产量,砂壤土以施氮255 kg/hm2时最高,分别为45.1%和10594 kg/hm2;而粘壤土施氮150~360 kg/hm2之间,氮肥吸收利用率为20.9%~22.4%之间,产量为10486~10596 kg/hm2之间;当对砂壤土和粘壤土的水稻穗肥施用氮肥时,水稻氮肥吸收利用率(分别为42.8%、23.5%)和产量(分别为10445 kg/hm2、10564 kg/hm2)最高。水稻的氮素收获指数、氮肥农学利用率、氮肥生理利用率及氮肥偏生产力,均以砂壤土明显高于粘壤土,且随着施氮量的增加而显著下降。蔬菜后作水稻施氮量以150~255 kg/hm2范围为宜,氮肥分基肥50%+分蘖肥30%+穗肥20%施用。

Effects of Different Fertilization on Yield, Nitrogen Absorption and Its Use Efficiency of Ricein the Northern Agricultural Area of Fuxian Lake

In the light of effects of excessive residual amount of soil nutrient on succeeding rice fertilization, arising from excessive vegetable fertilization in the northern agricultural area of Fuxian Lake, different fertilization experiments were carried out by field plots. The results showed that nitrogen-accumulation of rice was increased with increasing of nitrogen fertilization (150-360 kg/hm²) in sandy loam and clay loam, and the incremental nitrogen-accumulation was occurred in stem and leaf. The application of nitrogen in panicle fertilizer could increase nitrogen-accumulation of the grain. When applied nitrogen of 255 kg/hm², nitrogen use efficiency and yield of rice in sandy loam were showing the highest (45.1% and 10594 kg/hm²), when applied nitrogen between 150 kg/hm² and 360 kg/hm², nitrogen use efficiency and yield of rice in clay loam were 20.9%-22.4% and 10486-10596 kg/hm². When applied nitrogen in panicle fertilizer, nitrogen use efficiency and yield of rice were the highest in sandy loam (42.8% and 10445 kg/hm²) and clay loam (23.5% and 10564 kg/hm²). The nitrogen harvest index of rice, nitrogen agronomy efficiency, nitrogen physiological efficiency and nitrogen partial factor productivity in sandy loam were obviously higher than those in clay loam, and these were significantly decreased with increasing of nitrogen fertilization. The appropriate nitrogen fertilization of vegetable succeeding rice was 150-255 kg/hm², which were applied as base fertilizer (50%), tillering fertilizer (30%) and panicle fertilizer (20%).