Effect of composted chicken manure on cocoa crop nutrition in agroforestry systems in Panama

Aim of study: The objective was to determine the effect of organic fertilizer, composted chicken manure, on improving nutrition in cocoa crops for good vegetative development. Area of study: The study was carried out in 2019-2020 in Almirante, Bocas del Toro province, Republic of Panama. Material and methods: The study was carried out with 126 fine aroma cocoa plants in a 2,000 m2 agroforestry system. The statistical design was completely randomized blocks with 7 different doses of composted chicken manure (0, 5, 10, 15, 20, 25 and 30 Mg ha-1) 3 repetitions. The composted chicken manure was incorporated into the soil 15 cm from the tree. Leaf, plant and soil samples were taken one year after the doses were applied, at depths of 0 to 5, 5 to 15 and 15 to 30 cm. Main results: It was shown that the application of composted chicken manure increased the concentration of soil organic carbon, the pH and bioavailability of N, P, K and other essential elements, decreasing the concentration of aluminum in the soil. This leads to the balance of nutrients in the soil, resulting in a greater tree biomass. Research highlights: Composted chicken manure with doses higher than 20 Mg ha-1 contributed to the nutrition and growth of the cocoa crop, improving its tree development in a greater productive capacity.