Soil compactation on Producing Layers Through No-Tillage and Minimum Tillage Systems

The handling systems can affect physical qualities of agricultural soils as density and porosity, as well as the organic matter reserves distributed on agricultural layerâs profile. This trial aimed at evaluating the effect of no-tillage and minimum tillage systems: no-tillage system during four consecutive years (NT4); minimum tillage after four consecutive years with direct no-tillage system (MT4); no-tillage system during eight consecutive years (NT8) and; minimum tillage after eight consecutive years with no-tillage system (MT8). Cultures as soybean and maize were carried out in this field, the first one on summertime and the second in the winter with the same motomechanized sets for sowing, spraying and harvesting activities. The yield of soybean culture, soilâs density, particle density, organic matter, total porosity, porosity of adding (microporosity) and structural porosity (macroporosity) were evaluated, regarding depths from 0 to 0.05; 0.05 to 0.10; 0.10 to 0.15 and 0.15 to 0.20 m, which were collected at three different periods: one day after the cultureâs implantation; 60 days after the sowing and on the harvest day. This trial was carried out in Distroferric Red Latosoil, in Medianeira (PR). The results showed that soilâs density decreased with the MT4 and MT8 minimum tillage systems; and the total porosity and structural porosity increased proportionally when density decreased. The average results from organic matter were statistically similar for all the tillage systems, even though they have shown a significantly difference among the studied layers, with the greatest value. The band of the worked area has four and eight years with no-tillage were evaluated in relation to the water text in the ground of 10 to 24% and 15 to 24% respectively. The soybean yield was 12 % greater for the NT4 and NT8 no-tillage systems.%%%%Os sistemas de manejo podem afetar a qualidade fAsica dos solos agrAcolas como: densidade, porosidade, alAm das reservas de matAria orgAnica distribuAdas no perfil da camada agricultAvel. Este trabalho teve o objetivo de avaliar o efeito dos sistemas de cultivo mAnimo e plantio direto: plantio direto durante quatro anos consecutivos (PD4); cultivo mAnimo apAs quatro anos consecutivos com o plantio direto (CM4); plantio direto durante oito anos consecutivos (PD8) e cultivo mAnimo apAs oito anos consecutivos com o plantio direto (CM8). Foram trabalhadas nestas Areas as mesmas culturas, soja no verAo e milho no inverno, com os mesmos conjuntos motomecanizados para as atividades de semeadura, pulverizaAAo e colheita. Foram avaliados o rendimento da cultura da soja, os parAmetros de densidade do solo, densidade de partAculas, matAria orgAnica, porosidade total, porosidade de agregados (microporosidade), porosidade estrutural (macroporosidade), nas profundidades de 0 a 0,05; 0,05 a 0,10; 0,10 a 0,15 e 0,15 a 0,20 m, coletados em trAs Apocas distintas: um dia apAs a implantaAAo da cultura; 60 dias apAs a semeadura e apAs a colheita. O ensaio foi realizado em Latossolo Roxo, em Medianeira, regiAo…