Soil quality and diversity of macrofauna in cacao plantations and forest fragments in Waslala, RAAN, Nicaragua (May-December, 2010)

Abstract

The physical and chemical properties and diversity of soil macrofauna were evaluated in 36 cacao plantations and 4 forest fragments in the municipality of Waslala, RAAN, Nicaragua. At the center of each cacao plantation, a temporary measuring plot of 1000 m2 (20 x 50 m) was established. Five soil samples were taken at two depths (0-10 cm, 10-20 cm) and the physical and chemical properties of each were analyzed. The soil macrofauna was collected in three points of the plot, both in the litter and in the soil. At each point, a monolith (25x25x25 cm) was extracted and all organisms smaller than 2 mm in diameter were quantified and identified up to the taxonomic level of order. Based on physical-chemical indicators, 4 groups of soil quality were formed: the +Base group was classified as "Very Good", the ±bases and C groups are considered "Good" and the -Base group "Fair". All the macro and micro elements of the soil were found far from the critical ranges for the crop. 24 functional groups of macrofauna were identified, being the most abundant Formicidae (36%) and Oligochaetas (26%). The highest density of macrofauna was found in the quality group ± base (1174.8 individuals m-2) and the lowest density was recorded in the quality group C (929.3 individuals m-2). It is suggested to study the nutrient balance of the SAF-cocoa from Waslala to determine if the current fertility of the soil guarantees the sustainable production of cocoa.