Mineral nutrition of peach palm (Bactris gasipaes) in Amazonian agroforestry and recommendations for foliar analysis

Abstract

Peach palm (Bactris gasipaes) is an important tree crop in Amazonia. However, little information exists about the nutritional requirements of the species under the pedoclimatic conditions of the region, especially if grown under agroforestry conditions. Peach palm for palmito (heart-of-palm) production was grown in two agroforestry systems under four fertilization treatments. Yields were measured during three years in both systems, and soil analyses were carried out in one system. Leaf samples of three age classes were collected at four different times during a year. The annual palmito yields attained a satisfactory level of 0.4-0.85 kg per plant despite the infertile soil. They increased with increasing fertilization, in accord with the increasing nutrient availability in the soil, although the yield increases were not always significant. Dolomitic lime had a favorable effect on base saturation, exchangeable Ca and Mg in the soil and foliar Mg concentrations of the palms. According to the foliar analyses, the yield increases were probably due to a combination of P, Mg and possibly K. N fertilizer was taken up by the palms but did not seem to influence yields, in accord with the high N availability at the study site. The different Ca inputs had no effect on the palms. The more systematic use of foliar analysis for the optimization of fertilization schemes for peach palm in the region seems promising. Recommendations for the collection of leaf samples are also given. © 2002 Elsevier Science B.V. All rights reserved.