关于将氮肥运筹技术纳入农田杂草综合防除体系的思考

Management of Nitrogen Fertilizer Application Technique in Integrated Weed Control System in Crop Fields

我国是世界上化肥使用量最大的国家,面源污染和地力下降问题日益突出,为此农业农村部启动了"减肥减药"行动。杂草作为农田生态系统中除之不尽的植物,与作物存在复杂的竞争关系。前人研究结果表明,土壤养分状况影响作物和杂草间的竞争关系。那么,能否通过调节施肥量提高作物自身的竞争能力,从而降低杂草的危害,这为农田杂草的综合防控技术体系提供了新的思路和方法。因此,笔者建议以我国农田施用量最大的氮肥尿素和作物田优势杂草为研究对象,从植株构型和建成指标、氮代谢相关酶活性及其基因表达、同工酶谱的变化入手,从形态-养分-酶活性-基因4个层面系统阐述作物与杂草竞争关系响应氮素水平变化的生理与分子机理,以期为农田杂草综合防除体系中的氮肥运筹技术的形成提供理论依据。

China is the largest user of chemical fertilizers in the world. The problems of non-point source pollution and declining soil fertility are becoming increasingly prominent. Therefore,the Ministry of Agriculture and Rural Affairs has started the "Reduction of Fertilizer and Pesticide" action. Weeds are troublesome and difficult to control in the farmland ecosystem and interfere with crop production. Previous studies have found that competition between crop and weeds was affected by soil mineral nutrients,and then we presumed that the competitive ability of the crop can be improved by adjusting the concentration of soil nutrients. This constitutes a new idea and method to control weeds. Therefore,we suggested that the malignant weed species in crop fields in China be chosen as a model. Different levels of urea,the largest amount of nitrogen fertilizer for crop cultivation,were set to clarify the relationships between the changes of the plant architecture,morphogenesis index and the changes of nitrogen metabolism enzyme activity,gene expression and isozymogram. The physiological and molecular mechanisms of the response of competition between crop and weed to nitrogen stress will be clarified at the architecture-enzyme-gene activity levels. These findings would provide the theoretical basis to develop effective techniques to improve the competitive ability of crop to weed.