Crescimento de plathymenia reticulata BENTH. : sob diferentes doses de nitrogênio, fósforo e potássio em condições de campo

Abstract

The effect of fertilization on field growth of native forest species is of fundamental importance, since little information is available on the nutritional demand for better performance of these species. The objective of this study was to evaluate the effect of fertilization with the application of different nitrogen (N), phosphorus (P) and potassium (K) rates on mortality, growth (height and DAP), soil fertility, accumulated litter and Nutrients, and nutritional status of P. reticulata trees, three years after planting, in Sooretama-ES. The experimental design consisted of three blocks and 11 treatments (T1 = no fertilization; T2 = 20 g cova-1 of N, 27 g cova-1 of P2O5, 20 g cova-1 of K2O; T3 = T2 + 20 g cova-1 of N; T4 = T2 + 40 g cova-1 of N; T5 = T2 + 60 g cova-1 of N; T6 = T2 + 20 g cova-1 of P2O5; T7 = T2 + 40 g cova-1 of P2O5; T8 = T2 + 60 g cova-1 of P2O5; T9 = T2 + 20 g cova-1 of K2O; T10 = T2 + 40 g cova-1 of K2O; T11 = T2 + 60 g cova-1 of K2O). The forest inventory was carried out three years after planting in all the useful experimental plots with the measurement of the diameter at the breast height and the total height of all the trees, besides counting dead individuals. For the evaluation of the nutritional status of the trees, leaves were collected, submitted to chemical analysis. In each of the plots were collected 10 samples of accumulated litter to estimate the total biomass and determination of the levels and, subsequently, the content of nutrients. At the same sites, simple soil samples were collected for chemical analysis. There was no influence on the different nutrient doses used for the growth data of the species. It was observed that the higher the dose of P used, the higher the mortality. The different doses did not interfere in the macro and micronutrients levels of the leaves nor in the biomass and nutrient levels of the accumulated litter. In the soil only, the reduction in the concentrations of the chemical attributes analyzed with the advance of the collection depth was observed, and only K + and Na + had differences between treatments, observed only in the first layer analyzed. In general, the different doses used in the experiment did not interfere in the planting of P. reticulata, which indicates that the species is not demanding in nutritional terms.