玉米间隔耕作秸秆条带还田增密集成技术光热资源利用效率评估

本研究以2019年辽宁省铁岭县蔡牛镇玉米间隔耕作秸秆条带还田增密集成技术示范区和普通农户种植区玉米为研究对象,分析了两个区域玉米的光温资源利用率、光能利用率和热量利用效率,并从叶片和冠层尺度净光合速率、光合生产能力与光合参数、地上生物量累积等角度分析了集成技术光热资源利用效率提高的原因。结果表明,玉米间隔耕作秸秆条带还田增密集成技术与农户技术相比,光温资源利用率、光能利用率和热量利用效率分别提高了8.6、0.25个百分点和19.4%。示范区各层叶片光合生产能力和光合作用参数均显著高于农户技术;吐丝期至籽粒形成期示范区冠层日净同化量累积较农户技术高35.5%;开花吐丝期前后示范技术地上生物量累积显著高出农户技术19.4%,利于籽粒形成,提高株籽粒数和产量。因此,玉米间隔耕作秸秆条带还田增密集成技术冠层结构设计合理,叶片和冠层尺度光合能力均优于传统农户技术,产量关键期（开花吐丝期前后）地上生物量累积速度快,是一种能有效提高玉米光热资源利用效率的技术模式。

Evaluating the radiation and thermal use efficiency of the integrated technology of maize straw returning with alternate tillage and density increase

This study took maize cultivated using demonstration technology(SF treatment) and ordinary farmers'' technology(CK treatment) as study objects and evaluated the radiation and thermal use efficiency of the two technologies. Reasons for improvements in radiation and thermal use efficiency were analyzed based on leaf- and canopy-level net photosynthesis rate, photosynthetic capacity and parameters, and cumulated above-ground biomass during the yield critical period. Results showed that compared with the CK, the utilization ratio of radiation temperature and energy of SF treatment increased by 8.6 and 0.25 percentage point, and the thermal use efficiency of the SF treatment increased by 19.4%. The photosynthetic production capacity and parameters of the SF, in particular, were significantly better than those of the CK. The accumulative daily assimilation during the silking-grain formation stage was higher in the SF, by 35.5%, than in the CK. The accumulative above-ground biomass during the anthesis-silking stage was higher in the SF, by 19.4%, than in the CK; this helped in grain formation and increasing the amount of grains per plant. Therefore, canopy construction is reasonable for maize straw returning with alternate tillage. The leaf- and canopy-level photosynthesis capacity of the SF is superior to the CK, and the rate of accumulative above-ground biomass during yield critical period is faster in the latter than the former. Thus, the higher radiation and thermal use efficiency of the demonstration SF technology can be applied widely.