Greener Journal of Soil Science and Plant Nutrition Vol. 1 (2), pp. 016-022, July 2014.
© 2013 Greener Journals
Manuscript Number: 010614018
Agroforestry Trees as Source of N for Sustainable Alley Cropped Maize (Zea Mays L.) Yield on Depleted Loamy Soils
Department of Soil and Plant Sciences, Faculty of Agriculture and Natural Sciences, Great Zimbabwe University,
P. O. Box 1235. Masvingo. Zimbabwe.
*Corresponding Author’s Email: kasirayi @ gmail .com, Tel: +263773204291
The effects of leguminous agroforestry trees as sources of N for sustainable performance of alley cropped maize on depleted loamy soils were investigated under field conditions. The hedgerow species studied were Leucaena leucocephala, Senna siamea and Flemingia macrophylla. This study was superimposed on an existing ICRAF alley cropping trial at Chalimbana, Zambia. In this experiment, maize (variety MM 603), was the companion crop and the leguminous species comprised the alley hedgerows. Supplementary low levels of N (0 kgha-1, 34 kgha-1, 68 kgha-1 and 112 kgha-1) were applied. Tree litter was incorporated at 5 tha-1 for all species. There was no significant species effect on maize yields. A significant N fertiliser effect on yield was obtained at 68 kg N ha-1. This result probably indicates the need for moderate fertiliser N addition to incorporated residues so as to sustain maize yields in alley cropping.
Keywords: leguminous agroforestry trees, alley cropping, hedgerows, companion crop, depleted loamy soils, sustainable yield.