Efeito de diferentes fertilizantes no crescimento de quatro espécies de Mata Atlântica

Abstract

The fragmentation of natural ecosystems due to human activities has led to environmental degradation, loss of biodiversity, and ecosystem functions. Deforestation impacts the soil physically, chemically, and biologically by reducing the input of organic matter from leaf litter, which is essential for soil nutrition. This reduction in nutrients can significantly affect plant development, especially in the early stages. The objective of this study was to evaluate the effect of fertilization with different sources of nitrogen on the initial growth of four tree species from semi-deciduous seasonal forest (SSF). To this end, a nursery experiment was conducted, with a completely randomized design composed of five treatments of different types of nitrogen addition to the soil: 1) control (CNT) – no nutrient addition; 2) organic compost (COMP) – addition of compost made from food industry waste; 3) NPK – addition of chemical fertilizer composed of nitrogen (N), phosphorus (P) and potassium (K), in the proportion 4-14-8; 4) Green Manure (NV) – addition of compost made with macerated aerial parts of Gliricidia sepium; 5) NVME – addition of NV with a mixture of Efficient Microorganisms (EM). The species evaluated were: Tapirira guianensis Aubl; Gallesia integrifolia (Spreng.) Harms.; Cariniana legalis (Mart.) Kuntze; Casearia sylvestris Sw.. Each treatment received the same initial amount of nitrogen (N) in the soil. Based on the Gompertz non-linear model, the highest asymptote values of the growth curves, which represents the final size of the plants, were observed in the NPK, NVME, and NV treatments. The shapes of the growth curves and the chlorophyll content in the leaves over time suggest that, in general, the addition of NPK resulted in high amounts of nitrogen in the soil, but only at the beginning of the growth period, approximately 68 days from the start of the experiment. On the other hand, when adding NV and NVME, nitrogen remained available for longer period, resulting in prolonged growth over time. The addition of nitrogen via compost (COMP) resulted in lower growth rates, not differing from the control. The highest amount of total N in the soil after the end of the experiment was observed in NVME, suggesting that in the field, this treatment may result in high growth rates for a longer period. Additionally, the highest activity of the arylsulfatase enzyme was observed in NVME and COMP, indicating higher biological activity in the soil of these treatments, respectively. The β-glucosidase enzyme did not differ significantly between treatments. However, field studies are necessary to prove the effectiveness, regarding the initial growth rates of Green Manure and the addition of EM in native tree species, which could result in higher survival and growth rates of native tree species in forest restoration actions.