Tillage intensity reduces the arbuscular mycorrhizal fungi attributes associated with Solanum lycopersicum, in the Tehuantepec Isthmus (Oaxaca), Mexico

摘要

Understanding the responses of arbuscular mycorrhizal fungi (AMF) attributes and soil properties to tillage intensity is useful for the management of agroecosystems, especially in tropical lands, which are under intense pressures for human activities. This study aimed to examine the AMF attributes such as spore-based species richness, spore density, and root mycorrhizal colonization in systems with different tillage practices (intensive, traditional, and conservation). The soil of the study systems were sandy loam, moderately alkaline, and showed low levels of inorganic nitrogen and available phosphorus. Conservation tillage displayed the lowest pH and the highest inorganic nitrogen, soil organic carbon, and soil organic matter levels. Traditional tillage showed the lowest available phosphorus concentrations and the highest electric conductivity levels. Conservation tillage system showed the highest AMF spore-based species richness, spore density, and root mycorrhizal colonization; in contrast to intensive tillage that showed the lowest values. Spore density was not affected by the tillage intensity. Spore density and root mycorrhizal colonization appeared to increase with low available phosphorus levels. Spore density seemed to decrease as the levels of soil organic carbon and sand increased; by the contrary, root mycorrhizal colonization appeared to increase with high soil organic carbon levels, and decreased as the levels of inorganic nitrogen increased. This study highlights the conservation tillage as a useful management tool for maintaining the AMF attributes and soil properties.