Cover crops affect the mineral nutrition of cocoa trees in full-sun cultivation system

Cover crops improve physical, chemical, and biological quality of the soil. However, in full-sun cocoa cultivation, this practice still requires evaluation. This study evaluated soil fertility and mineral nutrition of cocoa trees in full-sun system intercropped with cover crops in the initial phase of implementation. The experiment was conducted in full-sun cocoa cultivation system, with two years of implementation of the clone of cocoa trees CEPEC 2002. The soil of the experimental area is a Typic Hapludalfs. The climate of the region, is hot and humid tropical forest without dry season and the regional relief is characterized as undulating, with altitude of 60 m. The study evaluated cover crops (brachiaria, fabaceas, spontaneous vegetation, and uncovered soil (desiccated)) in two experimental years, 2020 and 2021. Soil sampling was carried in layer of 0-20 cm and cocoa leaves were collected in 2020 and 2021 for nutritional composition evaluation (macro and micronutrients). The brachiaria treatment increased potassium levels in the soil approximately 3 times compared to initial levels. The use of cover crops in cacao full-sun cultivation systems decreased foliars nitrogen and zinc and increased potassium levels in the evaluated years. But, the potassium remained below the appropriate levels for the crop. The study still needs a longer period to comprove the results observed, at this early stage, by use of the cover crops in soil fertility and nutrition of cocoa trees, in full-sun systems.