Soil Attributes Related with Production of Brazil Nut Tree (Bertholletia excelsa)

ABSTRACT In this study we analyzed the soil attributes related with variation in the fruit production of Brazil nut trees, as well as the nutritional status of the species. Trees were selected in permanent plot (Caracaraí - RR) and divided in four production classes: High, Medium, Low and Very low. In November 2009, soil and leaves samples were taken to evaluate soil fertility, soil colonization by arbuscular mycorrhizal fungi, and trees nutritional status. Trees with higher fruits production occurred associated with higher exchangeable Al in soil depth of 0-20 cm, as well as to smaller pH and bases saturation values. The discriminant variable resulting of the present study was not assumed as responsible for interfering with the productive potential of Brazil nut trees; however, it indicates most productive trees contributing with exchangeable basis removal, favoring soil acidification.

摘要
本研究针对巴西坚果树（Brazil nut tree）果实产量变异相关的土壤属性，以及该物种的营养状况展开分析。研究于永久样地（巴西罗赖马州卡拉卡拉伊，RR）选取样树，并将其划分为高、中、低、极低四个产量等级。2009年11月采集土壤与叶片样本，用以评估土壤肥力、土壤丛枝菌根真菌（arbuscular mycorrhizal fungi）定殖情况以及样树的营养状况。研究发现，果实产量更高的样树与0-20 cm土层中更高的交换性铝（exchangeable Al）含量、更低的pH值及盐基饱和度密切相关。本研究所得的判别变量虽未被认定为干扰巴西坚果树生产潜力的因素，但该变量表明高产样树会促进交换性盐基的移除，进而加剧土壤酸化。