Long-term research on hedgerow pruning management for alley cropping in Haiti: implications for soil fertility maintenance and sustainability in low resource farming in the tropics

One of the basic concepts of alley cropping as practiced in the tropics is that the leaves and stems are used to add nitrogen and organic matter to the soil and recycle other plant nutrients. As I discussed the system with project leaders, I was made aware that the leaves and small stems of the trees were being removed to feed livestock or the hedgerows were heavily grazed by livestock. One of the purposes of designing this trial was to demonstrate the benefits to the crop of applying the hedgerow prunings to the alleys rather than removing them to feed livestock. Because of previous experience carrying out an alley cropping experiment in the Democratic Republic of Congo, I had become aware of the importance of managing the competition between the tree hedgerows and the associated crop through the timing of pruning operations. Therefore, I also felt it important to focus on identifying the proper timing and frequency of pruning operations during a growing season. Although this research was carried out in Haiti, the results relating to hedgerow management will be beneficial to those practicing alley cropping in other areas of the tropical world.