草是大自然中生态平衡的重要组成部分,有“大地之肺”的美誉。但有很多杂草投机钻营,混入栽培作物的行里株间,成为庄稼的大敌。农田杂草与农作物争地、争肥、争水、争光、争气、争温,是夺取粮油、瓜菜高产的重要障碍。有毒杂草危害畜牧业。萍类杂草是水生作物的大敌。茅、蒿类杂草的滋生妨碍山地药材和幼小林木成长。杂草适应性强,生长迅速,可在短期内侵占山谷、蔓延草原、堵塞河道。尽管人类已和它斗争了成千上万 Grass is an important part of the ecological balance in nature and has the reputation of “the lungs of the earth”. However, there are many weeds speculative drilling camp, mixed with cultivated crops in the line between strains, as the enemy of crops. Farmland weeds and crops compete for land, fight fat, fight for water, win glory, strive for war, fight temperature, is to seize grain and oil, vegetables, an important obstacle to high yield. Poisonous weeds endanger livestock husbandry. Ping weeds are the enemy of aquatic crops. Mao, Artemisia weeds impede the growth of mountain herbs and young trees. Adaptability of weeds, rapid growth, can invade the valley in the short term, the grasslands spread, blocking the river. Although human beings have struggled with it by thousands