免耕法对棉田生态系统能流功能的影响

比较了常规与免耕法对棉田生态系统中土壤微生物、害虫、天敌、棉株及其整个棉田生态系统能流功能的影响 .结果表明 ,免耕棉田土壤微生物量与年呼吸耗氧量均明显高于常规棉田 ,分别为常规棉田的 1 .32倍和 1 .63倍 ;免耕棉田的苗蚜与秋蚜、2代与 4代棉铃虫种群生产力下降 ,而伏蚜与 3代棉铃虫种群生产力增加 ;免耕棉田内天敌种群生产力及其捕食利用效率下降 ;免耕可提高棉田系统的光能利用率和总生产力 ,减少辅助能的投入 ,具有低耗、高效的特点 .

Effect of no tillage on energy flow in cotton agroecosystem.

Comparative studies on the effect of conventional and no tillage methods on soil microbes, insect pests, natural enemies, cotton plants and energy flow in cotton agroecosystems show that the biomass and respiration rate of soil microbes were respectively 1.32 times and 1.63 times higher in no tillage than in conventional cotton agroecosystem. In no tillage cotton agroecosystem, the productivity of seedling aphid (Aphis gossyppi), autumn aphid, 2nd and 4th generation cotton bollworm (Helicopavar armigera) populations was increased, but the productivity of summer aphid and 3rd generation cotton bollworm populations and the productivity and prey utilization efficiency of natural enemy populations were decreased. No tillage could enhance the light utilization efficiency and gross production, with an additional benefit of reduced energy expense in cotton agroecosystem.