Partição e acúmulo de macro e micronutrientes no abacaxizeiro submetido a doses de nitrogênio e densidades populacionais

Abstract

Studies related to absorption capacity and nutrient exportation by irrigated pineapple are important for the definition of appropriate doses and fertilization management. This study aimed to evaluate the accumulation of biomass, macro and micronutrients in the compartments of the irrigated 'Vitória' pineapple in semiarid after use of doses of nitrogen and different population densities. The treatments were arranged in a factorial scheme, with randomized block design with three replications and five doses of nitrogen (0, 5, 10, 15 and 20 g plant) and four planting densities (51,282, 76,923, 90,909 and 126,984 plants ha). We evaluated the biomass and nutrients accumulation in the compartments of the pineapple at the end of the crop cycle. Increasing doses of N combined with increasing plant population provided linear increase in vegetative growth and nutrient accumulation by pineapple. The leaves showed the highest accumulation of nutrients, followed by shoots, stem, fruit, crown and root. The pineapple showed the following order of decreasing nutrients uptake: K > N > Ca > P > Mg > S > Fe > Zn > Mn > B > Cu. In the population of 126,984 plants ha with 20 g planta of N, they were exported by fruits from the cultivated area: 1311.38 kg ha¹ of K (11.97%); 149.55 kg ha¹ of N (8.98%); 144.16 kg ha Ca (11.09 %); 52.16 kg ha¹ P (11.09%); 45.70 kg ha¹ Mg (12.00%) and 35.49 kg ha¹ S (11.87%), and by the shoots; 2425.79 kg ha¹ of K (22.14 %); 479.77 kg ha N (28.81 %); 147.30 kg ha¹ Ca (11.33%);100.85 kg ha of P (21.44%); 66.56 kg ha¹ Mg (17.49%) and 45.16 kg ha¹ S (15.10 %). There was greater exportation of macronutrients by shoots than by fruits, being 16,660.9 g ha of Fe (10.8%), 13,115.4 g ha of Mn (20.9%), 2,292.8 g ha¹ of Zn (9.8%), 2,050.2 g ha¹ of B (17.7%) and 1,322.6 g ha of Cu (22.7%) exported by shoots, and 12,693.8 g ha¹ de Fe (8.2%), 4.158,2 g ha¹ de Mn (6.6%), 1,824.4 g ha¹ of Zn (7.8%), 795.2 g ha¹ of B (6.8%) and 191.41 g ha of Cu (3.3%) exported by fruits in the highest plant population and doses of N.