Changes in Soil Microbial Activity and Community Composition as a Result of Selected Agricultural Practices

Abstract

For a constantly growing human population, healthy and productive soil is critical for sustainable delivery of agricultural products. The soil microorganisms play a crucial role in soil structure and functioning. They are responsible for soil formation, ecosystem biogeochemistry, cycling of nutrients and degradation of plant residues and xenobiotics. Certain agricultural treatments, such as fertilizers and pesticides applications, crop rotation, or soil amendment addition, influence the composition, abundance and function of bacteria and fungi in the soil ecosystems. Some of these practices have rather negative effects; others can help soil microorganisms by creating a friendlier habitat or providing nutrients. The changes in microbial community structure cannot be fully captured with traditional methods that are limited only to culturable organisms, which represent less than 1% of the whole population. The use of new molecular techniques such as metagenomics offers the possibility to better understand how agriculture affects soil microbiota. Therefore, the main goal of this review is to discuss how common farming practices influence microbial activity in the soil, with a special focus on pesticides, fertilizers, heavy metals and crop rotation. Furthermore, potential practices to mitigate the negative effects of some treatments are suggested and treatments that can beneficially influence soil microbiota are pointed out. Finally, application of metagenomics technique in agriculture and perspectives of developing efficient molecular tools in order to assess soil condition in the context of microbial activities are underlined.