LAUSR

Forage cactus responds positively to organic fertilization. However, little is known about the mineralization dynamics of the various sources of existing organic fertilizers. Thus, the objective was to evaluate the release of nutrients from different manure types and the nutrient accumulation in forage cactus across different cropping systems. Different manure sources (cattle, goat, sheep, and broiler litter) were evaluated for the following cropping systems: (i) Gliricidia sepium intercropped with cactus cv. IPA-Sertânia; (ii) Leucaena leucocephala intercropped with cactus cv. IPA-Sertânia; and (iii) Cactus cv. IPA-Sertânia in monoculture, in the tropical semiarid region of Brazil. The rate of decomposition and release of N, P, and K from manure was determined by incubating a litterbag, evaluated in different periods (0, 4, 8, 16, 32, 64, 128, and 256 days). Broiler litter released the greatest amount of N and P. Sheep manure released the greatest amounts of K. The greatest accumulations of N, P, and K in cactus biomass occurred when broiler litter was applied. Cactus monoculture accumulated less N over 256 days, indicating that the presence of tree legumes favors the accumulation of N in cactus. Broiler litter promoted the best synchronism between N release and N uptake in different cropping systems.