小麦-玉米周年秸秆还田对玉米害虫及天敌的影响

Effects of Annual Straw Returning Mode of Wheat and Maize on the Occurrence of Maize Pests and Natural Enemies

[目的]明确秸秆周年还田、耕作深度与施用腐熟剂对玉米害虫及天敌发生的影响,确定适宜的还田耕作深度和秸秆腐熟剂施用。[方法]在大田条件下分析了秸秆不还田+浅耕、秸秆还田+浅耕、秸秆还田+深耕、秸秆还田+深耕+腐熟剂处理对玉米害虫、天敌发生的影响。[结果]玉米田内害虫种群数量以秸秆还田+深耕+腐熟剂处理最低,秸秆还田+浅耕、秸秆还田+深耕处理次之,秸秆不还田+浅耕最高。蜘蛛类和天敌总量在4种秸秆还田模式中无显著差异。天敌与害虫的益害比受不同秸秆还田处理的影响:与秸秆不还田+浅耕对照相比,秸秆还田+深耕+腐熟剂、秸秆还田+浅耕、秸秆还田+深耕处理的益害比分别是对照的1.68、1.63和1.45倍。秸秆还田不同处理下亚洲玉米螟的发生量以秸秆还田+深耕+腐熟剂处理最低,与秸秆不还田+浅耕相比发生量下降(29.17±9.36)%。[结论]在推广秸秆还田模式中,可考虑秸秆还田结合深耕且施用腐熟剂的耕作方式,既能降低玉米田害虫的发生,又能提高天敌的控害能力。

[Objective] To determine the effects of annual straw returning, tillage depth and straw-decomposing inoculants on the occurrence of maize pests and natural enemies, and select straw returning manner that were suitable for controlling main pests in maize field. [Method] This study evaluated the effects of four straw returning manner(shallow tillage but not add straw returning, shallow tillage with straw returning, deep ploughing with straw returning, and deep ploughing with straw returning added straw-decomposing inoculants) on occurrence of pests, natural enemies and Ostrinia furnacalis under field conditions. [Result] The results indicated that within the investigation period, the number of pests was lowest in deep ploughing with straw returning added straw-decomposing inoculants, followed by shallow tillage with straw returning and deep ploughing with straw returning, the highest in shallow tillage but not add straw returning. However, the number of spiders and natural enemies of these pests were no significant difference among the four treatments. Ratio of natural enemy to insect pests was also different among the four straw returning manners. Ratio in deep ploughing with straw returning added straw-decomposing inoculants, shallow tillage with straw returning, deep ploughing with straw returning were 1.68,1.63 and 1.45 times as shallow tillage but not add straw returning, respectively. The number of O. furnacalis was lowest in deep ploughing with straw returning added straw-decomposing inoculants, decreased by(29.17±9.36) percent as shallow tillage but not add straw returning. [Conclusion] All the above results indicated that deep ploughing with straw returning added straw-decomposing inoculants could be used in straw returning technology popularizing, since it not only had significant control efficacy to pests, but also could increase the natural enemy activities of pest control.