Avaliação de bioporos do solo em condições subtropicais: características visuais do perfil do solo

Abstract

Brazil has become a major grain producer worldwide and as a consequence the impacts caused by the production system on agricultural soils are common. The soil has the function of providing the necessary support for the growth of plants, analyzes appear that serve as indicators of soil quality and are quantified in a chemical, physical and biological manner, with good results, but analyzes are usually quantitative, and in most of the times without accessibility for farmers. The objective of this work was to evaluate the methodology of soil biopores with a qualitative approach, aiming to visualize physical, chemical and biological characteristics in a single analysis. The work was carried out at the Unioeste experimental farm in Entre Rios do Oeste - PR and consisted of the evaluation of different crops (soybean, corn in organic area and soybean preceded by rye, soybean preceded by turnip + black oat and soybean preceded by fallow in system conventional) at different depths (10 cm, 20 cm and 40 cm). Trenches measuring 0.5 x 0.5 m were opened, and photographs were taken for further digital analysis. The results demonstrate that the methodology is able to make visible specific conditions such as water deficit, presence of macrofauna and galleries left by macrofauna organisms and plant roots. With such information, it is possible to make inferences about the quality of the soil. As the results obtained, it was possible to observe the growth of roots inside the soil's biopores in a preferential way and thus verifying the preference for the location, since the chemical and physical conditions present better conditions in relation to to the rest of the soil, it was also possible to verify the galleries of macrofauna organisms and again to verify the chemical, physical and biological conditions of the analyzed area based on the presence of these galleries. Thus, this analysis becomes a complementary alternative for evaluating the impacts of agricultural production on the soil, as it can be performed with simple equipment (cell phone, shovel, hoe and vacuum cleaner) quickly compared to other analyzes and has a complementary function to the range of existing methodologies. However, more studies are needed that correlate this approach with quantitative analyses, thus suggesting that future work studying this correlation is necessary.