Absorption of nutrients by soursop seedlings in response to mycorrhizal inoculation and addition of organic compost1

ABSTRACT The use of organic composts and the inoculation of arbuscular mycorrhizal fungi (AMF) are management alternatives in organic production systems. This study aimed to evaluate the effect of AMF inoculation (Acaulospora scrobiculata, Acaulospora colombiana and without inoculation) and organic compost of cacao bark (0 g dm-3, 5 g dm-3, 10 g dm-3, 20 g dm-3 and 30 g dm-3) on the mycorrhizal efficiency and nutrient uptake, in 'Morada' soursop seedlings. The experimental design was completely randomized, in a 3 x 5 factorial arrangement (AMF x organic compost), with four replicates. A higher mycorrhizal efficiency was observed for the A. colombiana isolate, with the addition of 0 g dm-3, 5 g dm-3 and 10 g dm-3 of organic compost to the soil, in relation to the A. scrobiculata isolate, which differed statistically at the doses of 20 g dm-3 and 30 g dm-3 of organic compost. The AMF inoculation promotes increases in the N, P, K, Zn, Cu, Fe and Mn contents, when compared to plants without inoculation. The organic compost exerts an effect on the inoculation, mainly on the absorption of P. The AMF inoculation, together with the organic fertilization, promotes the growth and nutrition of seedlings.