稻-鸭农作系统对稻田生物种群的影响

通过田间试验，研究了稻-鸭农作系统对稻田有关生物种群的影响.结果表明：稻鸭共育对稻田相关昆虫、杂草、病原菌等有害生物的发生和危害及天敌数量具有较大影响.与不养鸭相比，稻鸭共育后12 d和42 d, 水稻基部害虫飞虱及叶蝉的数量平均减少64.8%和78.5%；稻鸭共育后15 d和45 d，稻田杂草平均减少67.7%和98.1%；水稻分蘖高峰期和齐穗期的纹枯病病情指数分别降低了40.4%和62.0%.稻鸭共育还增加了稻田害虫天敌蜘蛛的数量，抑制了水稻害虫的危害.

Effects of rice-duck farming system on biotic populations in paddy field.

A field experiment was conducted to study the effects of rice-duck farming on the related biotic populations in paddy field. The results showed that rice-duck farming had greater effects on the occurrence and damage of pests, pathogens and weeds, as well as the amount of pests' natural enemies in paddy field. The population of rice planthopper and leafhopper decreased by 64.8% and 78.5% after 12 and 42 days of duck-release, and the weeds decreased by 67.7% and 98.1% after 15 and 45 days of duck-release, respectively, compared with the control. The sheath blight index at the maximum tillering stage and full-heading stage in the rice-duck plots were 40.4% and 62.0% lower than those in the control plot, respectively. The population of spiders in duck-released field was increased obviously, which in turn decreased the damage of rice pests.