Produção de matéria seca e relação carbono/nitrogênio de plantas de cobertura pré-trigo na região sul do Brasil

Abstract

Currently, much is said about soil preservation and care in order to achieve high productive levels, preserving the soil microbiota, fertility and physical structure. In this context, in southern Brazil, there is the problem of what to cultivate in the autumn, in the off-season soy/wheat, so much so that many producers choose to leave the crop fallow during this period, because it is a very short period to produce some culture until the end of the cycle. Although, the presence of green cover on the soil is essential, since it hinders the erosion and, therefore, the loss of soil, fertilizers and pesticides, also helps to prevent emergence of difficult-to-control weeds; in addition, cover crops are allies in the incorporation of organic matter to the soil and some species also contribute to increase the availability of nitrogen and phosphorus in the soil through biological fixation. Thus, the objective of the study was to evaluate the dry matter production and the C/N ratio of the mix coverage Rx 210® + vetch, radish and fallow in the autumn period. One experiment, was implanted in a private property in the city of Vitorino - PR, with two fall ground cover crops, radish and Rx 210® cover mix + vetch and one area was left fallow (soybean crop residues). For this, the treatments were evaluated at three different times, at 30 days after sowing (DAS), at 60 DAS and at 90 DAS. The experiment was conducted in a randomized block experimental design, with three treatments (two soil covers and fallow), in six blocks, totaling 18 experimental units. It was concluded that the best option for the producer in this period of off-season, when there is a period of up to 60 days, is forage turnip. However, when has a period of up to 120 days between harvests, the best choice is the coverage mix, due to variety of plant species, each of which has a different composition and may bring a better return to the producer. It is not recommended to leave the area fallow.