玉米根茬还田能够改善土壤耕层理化性能,提高土壤肥力,消灭浅土层越冬害虫,抑制杂草生长。试验表明,玉米根茬在土壤中经90—110天完全分解后,土壤容重每立方厘米降低0.02—0.1克,孔隙度增加1.6—7.5%,耕层土壤碱解氮增加5.7ppm,速效磷增加2—5ppm,速效钾增加1.6—4.4ppm。1公顷玉米的根茬还田后相当于22—34立方米优质腐熟农家肥。连续三年根茬还 Maize stubble can improve soil physical and chemical properties, improve soil fertility, eliminate overwintering pests in shallow soil and restrain weeds growth. The results showed that after the corn stubble was completely decomposed in the soil for 90-110 days, the soil bulk density decreased 0.02-0.1g per cubic centimeter, the porosity increased 1.6-7.5%, the content of available nitrogen in the topsoil increased 5.7ppm and the available phosphorus increased 2-5ppm, available potassium increased 1.6-4.4ppm. 1 hectare of corn stubble after returning equivalent to 22-34 cubic meters of high-quality rotten manure. Root stubble for three consecutive years