Effect of Litter Quality and Inorganic-N on Decomposition and Nitrogen Release in Alley Cropping from Three Leguminous Agroforestry Tree Species Effect of Litter Quality and Inorganic-N on Decomposition and Nitrogen Release in Alley Cropping from Three Le

Abstract

ABSTRACT The effects of litter quality and inorganic nitrogen (N) on rate of decomposition and N release pattern by three leguminous woody species were investigated under field conditions by the litterbag technique. The research was carried out in Zambia. The alley trees were Leucaena leucocephala, Senna siamea and Flemingia macrophylla. Maize was the companion crop. Dried leaf litters were placed inside litterbags and buried into the top 10-15 cm depth of soil. The four inorganic N levels were 0, 34, 68, and 112 kgNha -1 . Samples were drawn at intervals of 2, 4, 8, 12, and 16 weeks and were analysed to determine remaining dry matter weight, N, lignin, cellulose, polyphenol and carbon. Major findings were that L. leucocephala and S. siamea decomposed significantly faster than F. macrophylla. It was also observed that the level of inorganic N had a significant effect on decomposition rate. These results show that both the chemical composition of plant residues and level of inorganic fertiliser N applied increased the rate of plant residue decomposition