Nematodes as soil quality indicators in coffee agroecosystems

Resumen

Coffee family farmers in the Zona da Mata region implemented agroforestry systems focusing
on the restoration of soil quality. The impact on soil quality of two agroecological –mature and
young- and two conventional coffee agroecosystems was studied and compared to a fragment
of Atlantic rainforest. Soil quality was assessed using physic-chemical characteristics together
with nematode base indices using: Maturity Index (MI), Plant Parasitic Index (PPI), Channel
Index (CI), Enrichment Index (EI) and Structure Index (SI). Nematode diversity was assessed
using the Shannon-Wiener Index (H’). Agroecological coffee agroecosystems improved soil
chemical characteristics. MI and PPI pointed out to the Atlantic rainforest as the most mature
system. CI was higher in the Atlantic rainforest and one conventional system, showing a predominant
fungal decomposition channel in these systems. The Atlantic rainforest had the most
structured soil food web (SI) and was the least nutrient enriched (EI) system. Diversity of nematodes
was higher in the Atlantic rainforest and in mature agroecological systems. These results
pointed to the Atlantic rainforest as a great example of high soil quality and suggest that mature
agroecological agroecosystems have the potential to achieve multifold objectives, increasing
soil fertility, enhancing soil diversity and maintaining a structured soil food web.