玉米与不同植物间作对田间杂草群落动态变化的影响

2008年和2009年对玉米苗期-拔节期、喇叭口期-授粉期、成熟期田间杂草群落的密度、生物量和多样性进行监测。结果显示,玉米与向日葵、苜蓿、甘薯、花生间作系统中,玉米-向日葵间作模式能明显降低田间杂草总密度和生物量,但抑制效果随着玉米的生长,越到后期效果越不明显,第二年的抑制效果也明显弱于第一年。2008年,玉米-向日葵间作处理杂草总密度在苗期-拔节期、喇叭口期-授粉期、成熟期分别是对照的44.46%、43.64%和76.23%,总干重分别是对照的12.65%、20.77%和58.14%;2009年,总密度在各时期分别是对照的78.33%、81.19%和88.26%,总干重分别是对照的52.99%、88.28%和83.55%。此外,玉米-向日葵间作还能提高成熟期田间杂草的生物多样性,2008年多样性指数是对照的1.15倍,2009年是对照的1.13倍。玉米与苜蓿、甘薯、花生间作模式与对照相比不能降低甚至还增加了田间杂草的发生与危害,但均比对照提高了杂草的生物多样性。初步表明,玉米与向日葵间作,既能增加农田生态系统的多样性,又有一定的控制杂草效果。

Effect of Maize Intercropping with Different Crops on Weed Community Dynamics in the Fields

Weed densities,weed biodiversity and weed biomass at seedling-jointing stage,trumpet-pollination stage,maturation stage of maize were monitored in 2008 and 2009.The result reveals that among the four intercropping systems,the mode of maize intercropping with sunflower can significantly reduce the density and total amount of weeds.However,this effect gets less valid as maize grow up.The effect in the second year is much weaker than that of the first year.In 2008,the total weed density at seedling-jointing stage,trumpet-pollination stage,maturation stage were 44.46%,43.64% and 76.23% of the control respectively,and the total dry weights of weeds were 12.65%,20.77% and 58.14% of the control.In 2009,weed densities were 78.33%,81.19% and 88.26% of the control,and the dry weight amounts were 52.99%,88.28% and 83.55% of the control respectively at the different growth stage.Besides,maize intercropping with sunflower increased indexes of weed biodiversity to 1.15 and 1.13 times than that of the control in 2008 and 2009 respectively.Other intercropping modes might even increase the weeds＇occurrence,diversity and harmfuluess,but increase the weed biodiversity in the field than that of control.This result indicates that maize intercropping with sunflower may increase ecological diversity in the field and control the weeds occurrence and farmfulness as well.