Cover crops as modifying agents of microbiological soil attribute

Abstract

Carbon sources are exuded and deposited by different soil cover plants. They promote growth, diversity and enhancement of soil microbial community functionality, due to organic matter degradation by participating in major biochemical cycles and the availability of inorganic nutrients to plants. In this way, it is necessary to evaluate the microbiological attributes of the soil after cover cropping, which allows for surveying and monitoring the soil quality, thereby enabling rapid responses in relation to managing changes in the soil. Thus, the objective of this study was to evaluate soil microbiological attributes and soybean grain yield under the influence of different cover crops. The experiment was installed in the year 2015. The treatments were constituted by the following vegetation coverages: sorghum, millet, Urochloa ruziziensis, forage turnip, Urochloa brizantha, crambe and fallow area, with cover crops sown in succession to the soybean crop for three years prior to the date of installation of the experiment .The evaluated parameters were soil microbial biomass carbon, soil basal respiration, metabolic quotient, enzymatic activity of acid phosphatase and soil β-glucosidase, plant phytomass produced by the different cover crops and soybean yield in each area. The use of cover crops promotes higher soybean yield. The microbial activity and its efficiency were modulated according to the type of cover crop used. Soil under sorghum mulch provided lower microbial efficiency. The U. ruziziensis plant residues remain for less time on the soil. The results show that U. brizantha may be the most suitable for its use as a soil cover plant, providing improvements in its attributes.