Residual effect of soil tillage on water erosion from a Typic Paleudalf under long-term no-tillage and cropping systems

• Published in: Revista Brasileira de Ciência do Solo 2013-12, Vol.37 (6), p.1689-1698
• Main Authors: Lanzanova, Mastrângello Enívar, Eltz, Flávio Luiz Foletto, Nicoloso, Rodrigo da Silveira, Cassol, Elemar Antonino, Bertol, Ildegardis, Amado, Telmo Jorge Carneiro, Girardello, Vitor Cauduro
• Format: Article
• Language: English
• Subjects: erosão do solo; escoamento superficial de água; plantas de cobertura; SOIL SCIENCE
• ISSN: 0100-0683; 1806-9657; 0100-0683
• DOI: 10.1590/S0100-06832013000600025

Soil erosion is one of the chief causes of agricultural land degradation. Practices of conservation agriculture, such as no-tillage and cover crops, are the key strategies of soil erosion control. In a long-term experiment on a Typic Paleudalf, we evaluated the temporal changes of soil loss and water runoff rates promoted by the transition from conventional to no-tillage systems in the treatments: bare soil (BS); grassland (GL); winter fallow (WF); intercrop maize and velvet bean (M+VB); intercrop maize and jack bean (M+JB); forage radish as winter cover crop (FR); and winter cover crop consortium ryegrass - common vetch (RG+CV). Intensive soil tillage induced higher soil losses and water runoff rates; these effects persisted for up to three years after the adoption of no-tillage. The planting of cover crops resulted in a faster decrease of soil and water loss rates in the first years after conversion from conventional to no-tillage than to winter fallow. The association of no-tillage with cover crops promoted progressive soil stabilization; after three years, soil losses were similar and water runoff was lower than from grassland soil. In the treatments of cropping systems with cover crops, soil losses were reduced by 99.7 and 66.7 %, compared to bare soil and winter fallow, while the water losses were reduced by 96.8 and 71.8 % in relation to the same treatments, respectively. Erosão ainda causa degradação do solo em todo o mundo e é uma das mais importantes fontes de poluição ambiental. Para atenuar esse problema, a mudança de manejo do solo é indicada, e o sistema plantio direto é a principal ferramenta utilizada. Com o objetivo de avaliar as alterações temporais das taxas de escoamento da água e das perdas de solo provocadas pela transição do preparo convencional do solo para o sistema plantio direto (SPD), um experimento de longa duração foi conduzido em um Argissolo Vermelho distrófico, na Universidade Federal de Santa Maria, RS, Brasil. Os tratamentos testados foram: BS - solo descoberto; GL - campo nativo; WF - pousio invernal; M+VB - consórcio de milho e mucuna-preta; M+JB - consórcio de milho e feijão de porco; FR - nabo forrageiro como cultura de cobertura de inverno; e RG+CV - consórcio de culturas de cobertura de inverno, azevém e ervilhaca. Os resultados evidenciaram que o preparo do solo promoveu aumento da erosão e do escoamento da água; consequentemente, os efeitos desses permaneceram significativos pelo menos três anos após a adoção do S