Effects of cattle and poultry manures on organic matter content and adsorption complex of a sandy soil under cassava cultivation (Manihot esculenta, Crantz)

This study examined the A and B horizons of deep, developed and moderately unsaturated sandy ferrallitic soils amended with cattle and poultry manures under cassava (Manihot esculenta Crantz) cultivation. Therefore, a plot experiment was carried out by using a randomized complete blocks design in 4 replications and fields treatments which included unfertilized (control) and one dose (10 t/ha) of both manures. The study of the different fractions of animal manures showed that the poultry had the greatest content of C (organic carbon), N (nitrogen), P (phosphorus), K (potassium), Ca (calcium) and C:N ratio (p < 0.01). However, the value of Mg (magnesium) in the studied manures was not significantly different (p < 0.01). The manure treatment significantly increased the soil organic matter contents from 0.46 to 2.8 and 1.1% respectively with poultry and cattle manures (p < 0.01). Organic fertilizer significantly increased the cation exchange capacity from 1.7 to 12.75 and 3.8 me:100 g and the bases saturation content from 47 to 80 and to 76% respectively with the poultry and cattle manures (p < 0.01). The organic fertilizer showed significant effect on earthworms populations Hyperiodrilus africanus (Oligochaeta, Eudrilidae) in the soil, with 128 and 85% respectively about the poultry and cattle manures compared to the control (p < 0.01).Key words: Cattle manure, poultry manure, cassava, organic matter, cation exchange capacity, basessaturation content