Assessment of N Availability of Roots of Selected Woody Species and Maize

Abstract

ABSTRACT An experiment was conducted to assess the N availability of roots of woody species and maize. The trial was conducted using a split-plot design with four replications. Four incubation periods (0, 2, 4 and 6 months) made up the main plots. There were six subplots, consisting of addition of fine roots (< 2 mm diameter) of four woody species(Dactylcidenici barteri, Senna siamea, Gliricidia sepium and Leucaena leucocephala) and maize(Zea mays), and a control with no roots added. Roots from four-month-old plants were used in this study. Maize as test plant was grown in pots containing sandy loam soil (Psammentic ustorthent). Incubation period of roots before planting maize increased maize dry matter yield and N uptake. Addition of Gliricidia and Leucaena roots which have high? content and low C/N ratio (13.1 and 14.0 respectively) improved maize dry matter yield and N uptake following 2 months incubation. Application of maize roots which have low N content and high C/N ratio (40.3) reduced maize dry matter yield and N uptake. Application of Dactyladenia and Senna roots had an intermediate effect on maize dry matter yield and N uptake. Maize dry matter yield and N uptake were significantly and inversely correlated with the C/N ratio of the added roots with 0, 2, and 6 months incubation. No relationships were observed between the other root chemical characteristics and maize dry matter yield, and N uptake.