Soil chemical attributes, biometric characteristics, and concentrations of N and P in leaves and litter affected by fertilization and the number of sprouts per the Eucalyptus L'Hér. Strain in the Brazilian cerrado

Abstract

Given the lack of recommendations for the fertilization of Eucalyptus clones in the second production cycle, the effects of fertilizer rates and the number of sprouts per strain in terms of the soil chemical attributes, biometric characteristics, and the concentrations of N and P in the leaves and in the litter of Eucalyptus L'Hér. in the Brazilian Cerrado were evaluated. The experimental design was a randomized block with four replicates, arranged in a 2 × 4 factorial scheme: one or two sprouts per strain; four fertilizer rates (0, 50, 100, or 200% of 200 kg ha-1 of the formula 06-30-06 + 1.5% Cu + 1% Zn) applied immediately after sprout definition. The option of one sprout per strain yielded higher contents of organic matter (K, S, B, and Mn) in the 0.20-0.40-m layer, the leaf chlorophyll index, the diameter at breast height, and the height of the Eucalyptus 44 months after the definition of sprouts. However, N and P leaf concentrations and the wood volume did not differ as a function of the sprout numbers. The fertilizer dosage did not influence the wood volume, even in sandy soil with low fertility. Approximately 86% of the wood volume was obtained from the supply of soil and root nutrient reserves and 14% of this productivity is due to fertilization minerals. The adequate fertilization in the first cycle of the Eucalyptus supplies almost the entire nutritional demand of the forest in the second production cycle.