小麦秸秆还田及水层深度对水稻机械化插秧田主要杂草种群发生规律的影响

Influence of wheat straw returning and water depth on weeds community in mechanized-transplanting paddy fields

本试验系统调查了水稻机械化插秧田杂草的发生规律,并研究了小麦秸秆还田及水层深度对水稻机械化插秧田杂草发生规律的影响.结果显示,水稻机械化插秧田杂草有2个出草高峰期,分别是水稻移栽后3 ～ 10d与移栽后20～30 d,水稻移栽后30 d出草基本结束,杂草发生总量达1 m2 86株.小麦秸秆还田能促进阔叶类杂草和莎草科杂草的发生；秸秆还田推迟水稻机械化插秧田杂草的出草高峰.田间湿润管理比2～3 cm常规水层管理的杂草发生量大；保持田间4～5 cm深水层,能有效控制杂草发生.

The occurrence regularity of weeds and effect of wheat straw returning and water depth on weeds commu-nity in mechanized-transplanting paddy fields were evaluated. There were two weed occurrence peaks, which were 3-10 dand 20-30 d after rice transplanting, respectively. After transplanting for 30 d, the occurrence of weeds ended, and thenumber was up to 86 weeds in 1 m2 . Wheat straw was favorable for the development of broadleaf weeds and cyperaceaeweeds. Wheat straw returning could delay the peak of weed occurrence. Weeds occured wilder in wet field than in paddyfields with depth 2-3 cm water. Water of 4-5 depth in paddy fields could inhibit weeds growth effectively.