规模化稻鸭生态种养对稻田杂草群落组成及物种多样性的影响

Effect of large-scale rice-duck eco-farming on the composition and diversity of weed community in paddy fields

为探索规模稻鸭生态种养稻田杂草群落的变化动态,运用植物群落生态的方法研究了规模稻鸭生态种养、常规稻鸭生态种养和水稻单一种植稻田杂草的群落变化特点及控草效果。结果表明:规模稻鸭生态种养杂草密度显著降低,与水稻单一种植比较防效为94%;水稻分蘖到孕穗期稻田杂草主要由看麦娘(Alopecuruspratensis)、稗草(Echinochhloa crausgalli)、狗牙根(Cynodon dactylon)、水花生(Alternanthera philoxeroides)、鸭舌草(Mouochoria vaginalis)、水竹叶(Murdannia triquetra)和鳢肠(Eclipta prostrata)组成,抽穗期到成熟期主要由水花生、稗草、狗牙根和水竹叶组成。研究还表明,规模稻鸭生态种养水稻分蘖期物种丰富度、Simpon指数、Shannon-Wiener指数略高于水稻单一种植,Pielou指数低于水稻单一种植;孕穗期到成熟期物种丰富度、Simpon指数、Shannon-Wiener指数低于水稻单一种植,Pielou指数显著高于水稻单一种植。水稻全生育期规模稻鸭生态种养与常规稻鸭生态种养比较稻田杂草密度、杂草生物量和多样性指数差异不显著,但杂草生物多样性指数略有提高。说明规模稻鸭生态种养显著改变稻田杂草的群落结构和组成,可抑制杂草发生危害,达到有效控草目的。

Changing characteristics of weed community,weed-controlling effect of large-scale rice-duck eco-farming （SF）,conventional rice-duck eco-farming （CF） compared to mono-cropping rice （CK） were analyzed in order to explore the dynamics of weed communities in large-scale rice-duck eco-farming paddy fields.The study shows that weed density in paddy fields significantly decreases with more than 94% grass-controlling effect under SF compared with CK.Before rice booting stage,weeds compose mainly of Alopecurus pratensis,Echinochhloa crausgalli,Cynodon dactylon,Alternanthera philoxeroides,Mouochoria vaginalis,Murdannia triquetra and Eclipta prostrata in SF.During heading to ripe stage,weeds are mainly A.philoxeroides,E.crausgalli,C.dactylon,M.triquetra.At tillering,species richness,Simpon index and Shannon-Wiener index are higher while Pielou index is lower in SF than in CK.From booting to ripening,weed species richness,Simpon index and Shannon-Wiener index are lower while Pielou index is significantly higher in SF than in CK.In the entire rice growth period,weed density,weed fresh weight and species diversity are not significantly different between SF and CF,but species diversity is higher in SF than in CF.SF changes the structure of weed community and decreases weed species diversity,effectively limiting weed infestation in paddy fields.