免耕夏玉米田杂草生态经济阈值研究

Research on Weed Eco-economic Threshold in No-tillage Summer Corn Field

为了明确免耕夏玉米田杂草的生态经济阈值,通过田间小区试验,采用添加法对田间杂草的种类和密度进行配置,田间小区完全随机区组排列,通过杂草密度与玉米产量损失率的关系计算杂草的生态经济阈值。结果表明,杂草密度(x)与玉米产量损失率(y)呈正相关,以拟合优度>0.90和残差平方和最小为条件对产量损失率曲线模型进行优选,其关系符合指数方程(y=46.4359-18.518e-x/21.9215-28.5039e-x/126.5527,R2=0.9609),免耕夏玉米田杂草的生态经济阈值平均为2.27株/m2。通过该模型可明确田间杂草所能允许的最低密度,从而指导对田间杂草的综合治理。

The experiment was conducted to determine the weed eco-economic threshold in no-tillage summer corn field. Field plots were random complete block design. Weed species and density were setup using additive method. Weed eco-economic threshold was calculated by the relationship between the weed density and yield loss rate. The results showed that, yield loss rate （y） correlated positively with weed density （x）. The fitted curve models were optimized by goodness of fit 〉0.90 and minimal residual sum of squares. Exponential model 46.4359-18.518e-x/21.9215-28.5039e-x/126.5527,R2=0.9609） was the optimum equation to fit for the relationship. Average eco-economic threshold in the field was 2.27 plants per m2. Permitted minimum weed density of the no-tillage summer corn field could be calculated by the model and instructed the weed integrative management.