据联合国粮农组织估计,全世界每年因杂草危害减产总值达204亿美元。据我国1973年调查估计,全国每年有三亿亩农田遭受较严重的草害,减产粮油150亿斤、棉花1000万担左右。张家口地区坝上地广人稀,耕作管理粗放,往往造成大面积草荒,甚至毁种绝收。 According to the UN Food and Agriculture Organization (FAO) estimates, the world’s total annual loss of weed caused by weeds reached 20.4 billion U.S. dollars. According to our survey in 1973, it is estimated that 300 million mu of farmland in China suffer more serious grass-roots damage each year, reducing the output of grain and oil by 15 billion kilograms and about 10 million tons of cotton. Zhangjiakou area on the vast dams sparsely populated, extensive management of farming, often resulting in a large area of ​​grassland wasteland, or even destroy the absolute harvest.