耕作方式和施氮量对稻茬小麦产量构成和群体质量的影响

以苏麦188为材料,在水稻秸秆全量还田条件下研究板茬、旋耕、耕翻等耕作方式和施氮量210kg/hm2、240 kg/hm2、270 kg/hm2对小麦群体质量和产量及其结构的影响,为稻茬小麦大面积机械化栽培提供参考。结果表明：板茬方式产量显著高于旋耕和耕翻；随施氮量增加,产量逐渐提高。产量在不同耕作方式与施氮量间存在显著的互作效应。相比其他耕作方式,板茬方式每穗粒数和千粒重较高；群体茎蘖数多,但分蘖成穗率不高、源库协调水平偏低,花后具有较高的光合生产能力。随施氮量增加,穗数和每穗粒数、群体茎蘖数和分蘖成穗率、花后光合生产能力以及源库协调性均呈提高趋势。说明,通过合理增施氮肥可以进一步改善板茬方式下小麦群体质量,协同提升产量构成因素,实现增产。本试验条件下采用板茬方式配以施氮量270 kg/hm2或240 kg/hm2处理产量最高。

Tillage Modes and Nitrogen Fertilization Rates Affect Yield Component and Population Quality in Wheat Following Rice

In a field experiment under the condition of rice straw returning, we took wheat variety‘Sumai 188’ as the material and investigated the effects of different tillage modes and nitrogen fertilization rates on wheat yield component and population quality, to provide reference for large area mechanized cultivation of wheat following rice. There were 3 tillage managements, including no-tillage, rotary-tillage and ploughing, as well as 3 nitrogen fertilization rates including 210 kg/hm2, 240 kg/hm2, 270 kg/hm2. The results showed that: the wheat yield under no-tillage was significantly higher than those under rotary-tillage and ploughing condition; the yield was improved gradually with the increase of nitrogen rates; a significant interaction effect was found between tillage modes and nitrogen rates on grain yield; compared with other tillage modes, wheat under notillage had higher grains per spike and 1000-grains weight, more tillers with lower percentage of earring- tillers, lower source- sink coordination, and better photosynthetic ability after the anthesis stage; with the increase of nitrogen rates, a consistent improvement was observed in spike number, grains per spike, tillagenumber, the percentage of earring-tillers, photosynthetic produce ability after the thesis stage, and source-sink coordination. These results suggest that appropriate increase of nitrogen fertilizers could improve grain yield by optimizing wheat population quality and synergistically enhancing yield components. The highest yield isachieved under the nitrogen rate of 270 kg/hm2 or 240 kg/hm2 under no-tillage mode.