Banca de DEFESA: LUANA DRAGO DE SOUZA

BEHAVIOR OF CARBON AND NITROGEN METABOLISM IN PAU-PRETINHO (Cenostigma tocantinum DUCKE) SEEDLINGS AS A FUNCTION OF NICKEL AND BIOCHAR DOSES.

Phytoremediation; Heavy metal; Attenuator; Metabolism

The use of plants with phytoremediation potential is a practice used in soils contaminated by heavy metals, which are environmental pollutants and their toxicity is a problem of global importance. The objective of this work is to evaluate the carbon and nitrogen metabolism of the species Pau-pretinho (Cenostigma tocantinum Ducke) regarding its tolerance capabilities to this type of stress subjected to doses of the heavy metal nickel chloride (NiCl2) and with the attenuator of metal in the soil, biochar from açaí seeds (Euterpe oleracea Mart), this by-product is abundant after the extraction of the juice. The application of new technologies allows us to find efficient ways to reduce waste and prevent this waste from accumulating. The use of açaí seeds in the production of biochar is a promising approach, it is a carbonized material that can be incorporated into the soil to improve its quality, fertility and also acts to sequester carbon to reduce the emission of greenhouse gases. The growth and biochemical metabolism of carbon and nitrogen (reducing and non-reducing sugars, total soluble carbohydrates, sucrose, amino acids, proteins, proline, glycine betaine, free ammonium, nitrate reductase) in Pau-pretinho seedlings were evaluated. The experiment was conducted in a greenhouse, in an area of the Institute of Agricultural Sciences (ICA), belonging to the Federal Rural University of the Amazon – UFRA, Belém-PA campus. The design used was completely randomized in a 4 x 3 factorial scheme with 5 replications, the 1st factor corresponds to the doses of nickel chloride (0 NiCl2, NiCl2 70mg/kg; NiCl2 100mg/kg; NiCl2 130mg/kg) and the 2nd factor corresponds the doses of biochar (0%; 3.5%; 7%), using 60 seedlings in total. The data obtained were subjected to analysis of variance using the F test (p<0.05) and the means were compared by the minimum significant difference using the Tukey test (p<0.05) and subjected to the regression test using the AgroEstat program. For the growth variables (height, stem diameter, root length, number of leaves) and chlorophylls A and B. Nickel provided a decrease as the doses were increased, resulting in lower production of root diameter and length. And chlorophylls A and B showed a high degree of significance in statistical tests. Interactions with Biochar will also be significant, showing that the Cenostigma tocantinum DUCKE species has potential for phytoextraction.