Good management practices favor soil microbial activity

The adoption of good management practices, such as the use of level cultivation and autumn cover crops, favors microbial activity, improving soil conditions. This is what the preliminary results of the subproject “Microbiological indicators of soil under direct planting, associated with other conservation practices in the Central-South region of Paraná” indicate. Conducted in the district of Entre Rios, in Guarapuava, the study is part of the Paraná Network of AgroResearch and Applied Training (Rede AgroParaná) – a partnership between SENAR-PR, Fundação Araucária and the Secretary of State for Science, Technology and Higher Education ( Seti).

Since April 2019, the study has been comparing microbiological indicators from three areas – called megaplots –, conducted in different ways: the first cultivated using the standard Direct Planting System (SPD) technique; the second, managed with good management practices and level cultivation, with autumn cover crops (such as forage turnip, oats and vetch); and the third, with terracing at a level and management similar to that of the first megaplot. By collecting soil samples – in the 0 to 10 centimeter layer – the researchers monitored microbiological parameters, such as basal respiration, carbon and nitrogen in bacterial biomass, spores of arbuscular mycorrhizal fungi and soil enzymatic activities.

“Soil samples were collected twice a year in each megaplot, always in the most superficial part of the soil, where there is more microorganism activity. These samples were evaluated in the laboratory, observing several parameters, according to standardized methodologies, used throughout the AgroParaná Network”, explains the subproject coordinator and professor at Unicentro, Adriana Knobb.

According to preliminary data, the second megaplot – managed with good management practices – has recorded better results with regard to microbial activity and presented parameters that indicate an increase in net gains in organic carbon content in the soil. In short, good practices contribute to better quality soil, which favors productivity. “This soil has a greater carbon input and greater incorporation of plant residues. This incorporation favors the activity of microorganisms and improves soil conditions”, summarizes the study coordinator.

The partial results obtained by the study also indicate that the third megaplot (maintained with terracing) has been achieving better performance in relation to the area cultivated with standard direct planting. “Significant differences were observed in relation to respirometry attributes, metabolic quotient, number of mycorrhizal spores and acid phosphatase. The results indicate that the adoption of terraces has promoted an improvement in soil quality”, observes Adriana.

The subproject coordinator also highlights that microbial activity is more effective in capturing in advance changes caused in the soil by management techniques or use. This is because microorganisms reflect changes that have occurred more quickly, compared to chemical and physical indicators. “Due to their activity, microorganisms are indicators that respond more actively to what is happening. Only then are the changes captured by physical and chemical indicators”, explains the professor.

Another important point is that the subproject has been conducted in an integrated manner with other microbiological studies, which are being developed in other regions, within the AgroParaná Network. “These results can help in making decisions regarding production processes, helping producers to define soil management and use. All of this contributes to the development of the State’s agricultural sector”, says Adriana.