我县地处华北平原北部边缘,土壤大部分为淋溶褐士、草甸褐土。土壤肥力属于中下等水平—缺氮少磷钾不足。1985年秋,我站由河北省微生物所引进联合固氮菌剂100斤,在全县40个乡小麦百亩麦田进行了试验示范,效果显著,施菌剂的平均亩产小奏279.7公斤,不施的亩产248.21公斤,增产8.7%。1986年秋购进联合固氮菌剂1.5万斤被群众抢购一空,施用面积达2万亩。通过1986年苗情调查和夏收测产表明,接种固氮菌剂小麦营养生长旺盛,次生根多,单株分蘖多。每亩增 My county is located in northern edge of North China Plain, most of the soil is leached brown, meadow cinnamon. Soil fertility belongs to the middle and lower levels - lack of nitrogen and phosphorus less than potassium. The autumn of 1985, I station by the Hebei Institute of Microbiology introduced joint nitrogen-fixing bacteria 100 pounds, 40 counties in the county of wheat acres of wheat field trial demonstration, the effect is remarkable, the average yield of fungicides small playing 279.7 kg, not Shi The mu yield of 248.21 kilograms, an increase of 8.7%. The autumn of 1986 bought 15,000 kg of joint nitrogen-fixing bacteria were sold out by the masses, the application area of ​​20,000 mu. Through the 1986 Miao survey and summer harvest measured that the inoculation of nitrogen-fixing bacteria strong vegetative growth of wheat, secondary roots and more tillers per plant. Increased per mu