Biological use coefficient of biomass of Tachigali vulgaris under phosphorus and potassium fertilization: Management technologies for sustainable production of bioenergy in tropical countries

Abstract

Studies dealing with the behavior, initial development, uptake and nutrient use efficiency of native Amazonian trees as a function of fertilization are extremely important to support actions for the recovery and management of degraded areas. The objective of this study was to evaluate the influence of fertilization with different levels of phosphorus (P) and potassium (K) on growth and nutrient use efficiency in Tachigali vulgaris plantation. The experiment was installed in a tropical climate region in eastern Amazonia, Brazil. Three doses of P (0, 65.22 and 130.4 kg ha-1) and three doses of K (0, 100 and 200 kg ha-1) were applied in a 3 x 3 factorial scheme and randomized block design, with 4 repetitions. Growth parameters, nutrient concentration in biomass, nutrient use efficiency (NUE), and biological use coefficient (BUC) were evaluated. T. vulgaris responded significantly to fertilization with P and K in the parameters evaluated. It produced two times more biomass at the age of three years. Fertilization with 65.22 kg ha-1 of triple superphosphate and 200 kg ha-1 of potassium chloride was efficient to increase height growth by 11.1% considering the 24 months of evaluation, compared to unfertilized plants. Mg is the most efficiently utilized nutrient in the biomass components of T. vulgaris, followed by P, S, K, Ca and N. The woody compartments of T. vulgaris showed the highest BUC values, which is highly desirable and of great interest for forestry