稻草加速腐解对华南稻区水稻产量及氮肥利用效率的影响

【研究目的】旨在研究华南稻区稻草还田技术，为稻草还田(快速)腐熟替代部分氮肥，科学减少化肥施用量提供技术支撑。【方法】稻草还田条件下设不同腐熟剂用量和氮肥减量组合观测水稻产量和氮肥利用效率的变化。【结果】稻草还田配施模式平均减氮20%(17%~33%)的情况下，平均产量略低于常规施肥模式，品种间存在差异，‘华航48’以氮肥减量1/6和30 kg/hm2腐熟剂、60 kg/hm2腐熟剂处理的产量均略高于对照，‘广8优金占’以不加腐熟剂和氮肥减量1/6、60 kg/hm2腐熟剂和氮肥减量1/3处理的产量最高，但差异均不显著。‘华航48’的稻草还田模式的氮肥农学利用效率和偏生产力平均提高了60.2%和35.4%。【结论】选择水稻品种‘华航48’，加速腐熟稻草还田替代减量化肥是可行的，是一条化肥减量和水稻稳产的有效途径。

Rapid Decomposition of Straw: Effect on Rice Yield and Nitrogen Use Efficiency in the Rice Region of Southern China

The objective is to study straw returning technology in the rice region of southern China, and to provide technical support for substituting straw returning (rapid) decomposition for some nitrogen and reduce nitrogen fertilizer use scientifically. Under the condition of straw returning, different decomposing agent quantities and nitrogen reducing combinations were set up, rice yield and nitrogen use efficiency were detected. Reducing 20% (17%-33%) nitrogen quantity under straw returning model, the average yield was slightly lower than that of conventional fertilizer model. However, there was difference between rice cultivars. The yield of‘Huahang 48’with the treatment of reducing 1/6 nitrogen quantity, 30 kg/hm2 decomposition agent and 60 kg/hm2 decomposition agent, was slightly higher than that of the control. The yield of‘Guang 8 youjinzhan’with the treatment of non decomposition agent and reducing 1/6 nitrogen quantity, 60 kg/hm2 decomposition agent and reducing 1/3 nitrogen quantity, was the highest, but the difference was not significant. In addition, nitrogen agronomy use efficiency and partial factor productivity of‘Huahang 48’under the straw returning model increased by 60.2% and 35.4% , respectively. Rice cultivar selection and straw returning (rapid) decomposition instead of nitrogen reducing is feasible, it is an effective way for nitrogen reducing and rice stable yield.