Impacts of different cacao (theobroma cacao l.) Agroforestry arrangements and farming systems on soil biodiversity in the ecuadorian amazon

Summary

In the last 15 years, the market for cacao and its by-products has been facing an increasing demand that is leading to agricultural intensification. The typical shade production of cacao has been replaced by high input monoculture system, causing soil degradation, including soil erosion and soil biodiversity loss. Cacao Agroforestry Farming Systems (CAFS) represent a valid solution in terms of soil health and biodiversity preservation. The objective of this study is to assess the effects of different farming management practices and different agroforestry systems on soil biodiversity. Free-living nematodes, earthworms, macroarthropods, and microbial communities have been characterized in a long-term field experiment from five different CAFS in the Ecuadorian Amazon region, from both organic and conventional treatments. Nematodes, earthworms, and macroarthropods were extracted from the soil and morphologically identified and quantified. The overall structure and diversity of the soil microbial communities were studied through Phospholipids Fatty Acids (PLFAs) and Neutral Lipids Fatty Acids analysis (NLFAs). Nematode-based indices (NBIs) (i.e., maturity index (MI), maturity index 2-5 (MI 2-5), structure index (SI), enrichment index (EI), channel index (CI), basal index (BI)) were calculated to assess the complexity of the soil food web and the resource flow into the soil webs. The arthropods-based index of biological soil quality (QBS) was used as an indicator for soil health. These parameters were related to soil chemical parameters, such as C: N ratio in the soil and the soil total available carbon, indicators for soil quality. The data are currently being analyzed; results will be presented during the conference.