Effect of No-Tillage Practice on the Production of Plants, Pests and Its Natural Enemies in Cotton Agroecosystem

摘要

The effect of tillage (conventional tillage and no-tillage) practices on production of plant, insect pests, and natural enemies were measured in cotton agroecosystems of Northern China. The results showed that 1.69 times and 4.62 times more cotton plants and weeds produced in no-tillage system than in conventional tillage system, respectively. The significant difference on the production of cotton bollworm (Helicopavar armigera) was found in two tillage systems. The production of 2nd and 4th generation cotton bollworm populations was increased and the production of 3rd generation cotton bollworm populations were decreased in no-tillage system. However, the production of cotton aphids and insect pest community are not significantly different between no-tillage and conventional tillage cotton agroecosystem. No-tillage practice has made different effect on natural enemies population. The production of predacious ladybeetles, predacious bugs and natural enemies community were decreased significantly in no-tillage system. However, no significant difference of the production of predacious spiders and parasites were observed in two tillage systems. From the view of interaction between plant, pest and natural enemies, the biological control effect (ingestion-utilization efficient) of natural enemies to pest community in no-tillage system are 53.57% of that of conventional tillage system. 1.1% of the ingestion and utilization efficient of pests to plants was increased in no-tillage system compared with the conventional tillage system. Light utilization efficient, cotton lint production and gross production in no-tillage system increased 1.70 times, 25.17% and 1.83 times compared with the conventional tillage system, respectively. Our results suggested no-tillage practice could enhance the light utilization efficiency and gross production, with an additional benefit of reduced energy input in cotton agroecosystem.