EFFECT OF SEASON ON THE VARIATION OF HERBAGE AVAILABIL ITY AND QUALITY IN COMMUNAL PASTURE AND CROP RESIDUE YIELD IN THE SAVANNA ZONE OF NORTHERN GHANA

Abstract

Herbage availability variation in pasture and crop residue yields were estimated as feed resources in northern Ghana. Data were collected across seasons for one year using a wooden meter square quadrat. Samples of pasture yield in 1-m2quadrat were taken randomly from communal grazing land and crop residues from cultivated fields at crop maturity. The data was analyzed with GenStat using ANOVA. Seasons were fixed factors with herbage yield/ha and nutritive parameters as variable factors. Results showed that quantity of herbage in the pasture across seasons varied significantly (P<0.05). The values were 3.0, 1.5, 0.5 and 2.0 tonnes DM/ha for early dry (November–January), late dry (February–April), early wet (May–July) and main wet (August–October) seasons, respectively. Highest (P<0.05) crop residue yield of 8.5 tonnes DM/ha was obtained in sorghum whereas cowpea had the lowest yield of 1.8 tonnes DM/ha. Crude protein content of commonly grazed pasture species differed (P<0.05) across seasons (75, 45, 174 and 165 g/kg DM for early dry, late dry, early wet and main wet seasons, respectively). Herbage availability in pasture during late dry season was 55% less than the amount available in early dry season; the season with highest amount of herbage. The quality was significantly lower in the late dry season indicating possible under-nutrition of animals if supplementary feeding is not done.