Review of research on nutrient contribution and recovery in alley cropping systems

Alley cropping is the farming system growing food crops between hedgerows of trees or shrubs(nitrogen fixing species). The hedgerows in the systems are regularly pruned to prevent shading companion crops and to provide prunings for mulch and manure to improve soil fertility. Nitrogen mineralization of branch and leaf of hedgerow, organic carbon mineralization of branch and leaf of hedgerow and its effects on soil organic matter as well as the supply situation of hedgerow on soil phosphorus and other mineral element were expounded. The dynamics of soil nutrien and organic matter under the system were reviewed.