Microbiological Assessment of Soil Planted with Cover Crops, and Soybean and Maize in Succession

Abstract

This study aimed to assess the population density of nematodes and mycorrhizal soil fungi, in areas cultivated with oats, brachiaria, forage and white lupine, as well as in maize and soybean crops in succession, in order to generate a microbiological indicator of soil quality. In order to assess nematode and arbuscular mycorrhizal fungi (AMF) population densities, the experiment was performed in two stages: the first assessment was performed in the area where different cover crops were planted, in five seasons (0, 60, 90, 120, 150 days after sowing—DAS). In the second stage, soybean and maize crops in succession were assessed. According to the results, free-living nematodes and arbuscular mycorrhizal fungi population densities were not affected by the cover crop species used and, therefore, these can be grown prior to soybean and corn crops, without impact to free-living nematodes and AMF. The largest population of saprophyte nematodes and AMF occurred at 90 days. The cultivation of soybean and corn did not influence the number of free - living nematodes, but influenced the number of arbuscular mycorrhizal fungi. The highest numbers of mycorrhizal fungi Gigaspora margarita and Glomus macrocarpum were found in maize.