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.

摘要：有机堆肥施用与丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）接种是有机生产体系中的可选管理措施。本研究以‘Morada’品种刺果番荔枝（soursop）幼苗为试材，旨在评估3种丛枝菌根真菌接种处理（皱缩无梗囊霉Acaulospora scrobiculata、哥伦比亚无梗囊霉Acaulospora colombiana以及不接种对照）与可可树皮有机堆肥不同用量（0 g dm⁻³、5 g dm⁻³、10 g dm⁻³、20 g dm⁻³、30 g dm⁻³）对幼苗菌根效率及养分吸收的影响。试验采用完全随机设计，设置3×5因子组合（AMF接种处理×有机堆肥用量），共4次重复。相较于皱缩无梗囊霉处理，哥伦比亚无梗囊霉菌株在土壤添加0、5、10 g dm⁻³有机堆肥时表现出更高的菌根效率；而当有机堆肥用量为20 g dm⁻³与30 g dm⁻³时，两种接种处理的菌根效率存在显著统计学差异。与不接种对照相比，接种丛枝菌根真菌可显著提升幼苗体内氮（N）、磷（P）、钾（K）、锌（Zn）、铜（Cu）、铁（Fe）及锰（Mn）的含量。有机堆肥对菌根接种效果具有调控作用，尤其对磷元素的吸收影响最为突出。丛枝菌根真菌接种配合有机施肥，可有效促进刺果番荔枝幼苗的生长与养分吸收。