Plant Age Influences Potassium Dynamics in Açaí Palm Cultivation Within Agroforestry Systems in the Eastern Amazon

Abstract

PurposeThis study aimed to investigate the impact of plant age on potassium (K) dynamics in açaí palm cultivation within an agroforestry system.MethodsThe experiment was conducted in Tomé-Açu, Pará, Brazil, using a split-block experimental design, with four replications and six treatments corresponding to plant ages (2, 3, 4, 5, 6, and 7 years). The concentration and accumulation of K, as well as nutrient use efficiency, immobilization, recycling, and export rates were evaluated. The results were subjected to variance analysis (p < 0.05) and regression model adjustments.ResultsThere was a positive quadratic response in K accumulation in plant organs as the açaí palm aged. Regarding K immobilization, recycling, and export rates, a quadratic increase was observed in plant parts as a function of age. For the evaluated ages, the highest proportion of K immobilization was found in the stipe, recycling in the leaflets, and export in the empty fruit bunches. K extraction, total requirement, and effective requirement also showed a positive quadratic response as plant age increased. The higher concentration of K in the fruits (açaí pulp) and meristem (heart of palm) meets the recommended daily intake of K for humans, indicating that they are important sources of this nutrient for human health.ConclusionsThis study provides valuable information on the adequate amounts of K in açaí for human consumption, as well as nutritional management strategies that consider the specific needs of açaí palms cultivated in agroforestry systems in the Amazon.