Effect of organic management on soil fertility and melon production in irrigated oasis farmlands

Organic management is an effective strategy for producing safe fruits and vegetables. To evaluate the effect of organic management on soil quality and melon production in dry regions, an open-field experiment was conducted in the lower reaches of the Shiyanghe River Basin. Melon yield and quality, soil nutrients, enzyme activities and quantities of microorganisms were determined in plots after different years of organic management. The results showed that organic management significantly increased soil organic matter and available N, P and K contents. After one, two and three years of organic management, soil organic matter content increased by 36.48%, 71.54%, 124.21% compared with traditional management, respectively. In three-year organic management plots, soil available N, P and K contents were significantly higher than that in traditional management plots. Compared with traditional management plots, soil available N, P and K contents in three-year organic management plots increased by 49.04 mg·kg-1, 65.68 mg·kg-1 and 214.62 mg·kg-1, respectively. Also compared with traditional management plots, soil fungi, bacteria and actinomycetes and activities of urease and alkaline phosphatase in organic management plots increased significantly. While no significant difference was noted in melon fruit yield between the two management practices, total soluble solids in melon flesh was significantly higher in organic management plots than in traditional management plots. These results suggested that organic management improved soil fertility, enhanced soil microorganism community, and increased soil enzyme activity and melon fruit quality.