Submitted to: World Agroforestry Congress
Publication Type: Proceedings
Publication Acceptance Date: 1/31/2009
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: In agroecosytems, the efficient nutrient cycling is considered responsible for plant nutrition; however it is important to consider the amount of total available nutrients. Experiments were undertaken to quantify the carbon stock and available nutrients in cacao plantation grown under tree shade of a system called “Cacao-Cabruca” system, in southeast region of Bahia state, Brazil. Sixteen Cacao-Cabruca systems were selected for this study. Soil samples were collected from 0-20 and 20-40 cm depth, and were analyzed for concentrations of organic carbon, calcium, magnesium, potassium, phosphorus, sulfur, boron, iron, manganese, copper and zinc. From these analyses the organic carbon stock and the total available nutrients in the 0-40 cm of soil depth were calculated. The average carbon stock observed in these Cacao-Cabruca systems was 87.3 t/ha. Average total available nutrients, observed/ha were, 4164.4 kg.Ca; 882.8 kg. Mg; 315.7 kg. K; 37.6 kg. P; 1.7 kg. B; 1091.5 kg. Fe; 96.8 kg. S; 27.6 kg. Cu; 307.9 kg. Mn and 49.3 kg .Zn. Considering the observed total available nutrients amounts and the carbon stock, it is fair to infer that the cacao cabruca system is fertile and requires no additional external nutrient inputs, with exception of phosphorus and boron. Since all the other nutrients determined were beyond the sufficiency of available nutrients quantity. The mineralization of soil organic matter is an important additional nutrient input to meet plant nutritional demand in this cacao cabruca system.