Effect of utilization deferment of Cenchrus ciliaris (L)-Leucaena leucocephala (Lam)(de Wit) association. I. Yield and composition of the dry matter.

An experiment was conducted in a semi-arid region located in the State of Zulia, western part of Venezuela (10º32'N and 71042'W, and 600 mm average annual rainfall), to evaluate the effect of the deferment of five utilization ages (DUA) 0, 42, 84, 126 and 168 days of buffel (Cenchrus ciliaris) - leucaena (Leucaena leucocephala) association on the dry matter yield (DMY) and composition DMC (leaf, stem and dead dry matter). Soil was a sandy loam Aridisol with pH 5,5. The average soil calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), and P contents were 0,6; 0,3; 0,1 and 0,17 meq/100g-1 soil and 6 ppm, respectively. Total dry matter yield (TDMY) and partial dry matter yield (DMY) for each one components in the grass profile (leaf, steam and dead matter) and legumes profile (fine fraction pinnas and stems < 5mm) and thick fraction: branches and stems > 5mm of diameter) were studied using a randomized blocks experimental design and three replications. The results did not evidence significant differences in the treatments for (TDMY) in both species with means of 1602 and 2869 for buffel and leucaena respectively. Leaf proportion was highest and dead matter was lowest (P<0,005) in buffel for 0 DUA. Deferment of utilization did not influence the fine fraction yield in leucaena which averaged 1189 kg/ha