Teor e aporte de nutrientes via biomassa de podas em sistema agroflorestal sucessional

Abstract

The aim of this work was to study nutrient-recycling species in an agroforestry system in the southwestern region of Paraná, assessing the nutrient content and contribution of biomass managed by pruning. Five species were analyzed: Bauhinia forficata (Pata de vaca), Ingá marginata (Ingá) and Leucaena leucocephala (Leucena) belonging to the Fabaceae family, Morus rubra (Amoreira) from the Moraceae family and Solanum mauritianum (fumeiro-bravo) from the Solanaceae family. The individuals of each species that had been measured and pruned in 2022 and pruned again in 2023 were marked. The methodology consisted of drastic pruning, measurement of fresh and dry biomass and laboratory analysis of carbon, nitrogen, phosphorus, potassium, calcium and magnesium content. There was no difference between the species in terms of biomass produced, but the species that showed the best results in terms of dry biomass was the pata de vaca with 12500 g/year-1. There was no difference between species in terms of the total amount of nutrients observed in the biomass of each species, but Leucena was the species that provided more nitrogen (315.3 g/year-1), potassium (227.6 g/year-1) and magnesium (28 g/year-1) than the other species. Mulberry stood out in terms of carbon sequestration (9000 g/year-1) and calcium (11 kg/year-1) and potassium (27.7 k/year-1). With the exception of phosphorus, which was found in the <3 fraction, the other nutrients were found in the leaf fraction. It was found that the nutrient input is directly linked to the nutrient content present in the biomass of each species, with the leaf fraction contributing the most to the nutrient input, except for phosphorus, which was found in the <3 fraction. The study revealed distinct distribution patterns between the fractions analyzed.