Abstract: In order to study the effect of planting winter green manure on soil fertility and cotton growth,using free time and interspace of winter free farmland in Northern China plain,two green manure varieties of vetch and Orychophragmus violaceus were planted before winter and then returned to the field before cotton sowing in the following spring.Three years later,the results showed that the top 0-20 cm soil fungi,bacteria and actinomycetes had a greatly increasing,soil invertase activity in 0-20 cm top soil also had a greatly increasing;Soil organic matter was increased from 8.65-8.74 g/kg to 11.08 g/kg,the content of soil total N was increased by 44%-50%;the content of Olsen-P was increased from 6.79-7.01 mg/kg to 12.80 mg/kg;and the content of available K was increased by 6.04%;The cotton boll number of green manure treatment was significantly higher than that without green manure and the seed cotton yield was increased by 7.03%-7.68%.Cotton interplanting green manure not only could enhance the soil fertility,and increase the yield of cotton,which has the important application value.

Key words: Cotton, Green manure, Winter-free farmland, Yield, Soil fertility

CLC Number: 

• S142

• S562.01