Matéria orgânica e infiltração da água em solo sob consórcio milho e forrageiras

Abstract

R ESU M OA infiltração é o processo pelo qual a água penetra no solo através de sua superfície e sua dinâmica pode ser condicionada por diversos fatores, dentre eles os sistemas de manejo do solo adotados. O objetivo deste trabalho foi estimar a velocidade de infiltração da água e os teores de matéria orgânica do solo em sistema de consórcio milho e forrageiras. O experimento foi realizado em delineamento de blocos casualizados, com três repetições. Foram estudados os efeitos de cinco tratamentos submetidos ao manejo de plantio direto: 1) Milho Solteiro (Zea mays L.); 2) Braquiária Humidícola (Brachiaria humidicola); 3) Consórcio Milho e Braquiária Humidícola; 4) Capim Aruana (Panicum maximum cv. Aruana); 5) Consórcio Milho e Capim Aruana. Utilizou-se, para determinação da velocidade de infiltração básica (VIB), o método dos infiltrômetros de cilindros concêntricos. Outros atributos físicos do solo e a matéria orgânica do solo foram avaliados buscando-se associá-los aos valores de VIB encontrados. Os resultados revelaram que sob plantio direto os sistemas apresentaram elevados valores de VIB. O sistema Milho Solteiro apresentou a maior VIB e a inserção de forrageiras nos sistemas provocou redução da VIB; todos os sistemas apresentaram diminuição dos teores de matéria orgânica em profundidade. Palavras-chave : infiltrômetro, plantio direto, água no soloSoil organic matter and water infiltration under maize and forage intercropping A B ST R A C T Infiltration is a process by which water penetrates through the soil by its surface, and its dynamics can be influenced by several factors, among them, the soil management system adopted. The objective of this work was to estimate water infiltration rate and soil organic matter content in maize and forage intercropping systems. The experiment was conducted in a randomized block design with three replications. Five treatments under no-tillage management were evaluated: 1) Corn (Zea mays L.), 2) brachiaria humidicola (Brachiaria humidicola), 3) Corn and brachiaria humidicola intercropping, 4) Aruana grass (Panicum maximum cv. Aruana), 5) Corn and Aruana grass intercropping. The double ring infiltrometer method was used to determine the basic infiltration rate (VIB). Soil physical properties and soil organic matter were evaluated and correlated with VIB values. Results revealed high VIB values for no-tillage. The highest VIB values were observed in the corn treatment. VIB values decreased with the inclusion of forages. All cultivation systems showed a decrease of organic matter with depth.

Changes in Chemical Properties by Use and Management of an Oxisol in the Amazon Biome

“…The minimum tillage area had higher organic matter content (Table 4) The continuous deposition of plant material and lack of soil tilling in native forest areas strongly contribute to increase the organic matter content in the soil (ARAÚJO et al, 2011;SATO et al, 2012). The soil tilling in conventional tillage contributes to the organic matter exposure and oxidation, thus, systems that have the less intense soil tilling, such as minimum tillage, contribute to increase the soil organic matter contents (BAYER; BERTOL, 1999).…”

“…Inadequate soil managements potentially contribute to environmental degradation, since it negatively changes the soil physical, chemical and biological characteristics (SILVA NETO et al, 2011). This processes are even more serious in the Amazon region, in which the conversion into pastures occurs often after the use of burning practices (TOWNSEND; COSTA; PEREIRA, 2010) and soil tilling by plowing and harrowing, causing destruction of aggregates, decrease of organic matter content in the soil surface layers and increase of water erosion (BAYER;BERTOL, 1999;MOREIRA;MALAVOLTA, 2004;SATO et al, 2012). Thus, the soil uses in this region must be carefully planned, implementing soil conservation practices from the beginning, in order to preserve the soil productive potential (MULLER et al, 2001).…”

Soybean Tillage Systems and Physical Changes in Surface Layers of Two Albaqualf Soils

“…The evaluations were performed in the planting row using the double ring infiltrometer method. Readings were taken over a 3-h period, as proposed by Sato et al (2012).…”

Runoff from soils under different management and simulated rainfall regimes in southern Brazil

“…Panachuki et al (2011), comparing no-till with and without residues on the surface, showed that infiltration was greater under the former. Sato et al (2012) showed that differences in infiltration rate could be related to rooting systems, and were influenced by growth and distribution of roots. Tomasini et al (2010) showed that mechanical harvesting reduces the infiltration rate relative to that for manual harvesting.…”

“…First, soil turnover leads to an increase in pore-size as shown by Lipiec et al (2006). Second, where soil is managed with little turn-over, the actions of roots, worms and insects present in soil favours infiltration of water (Govaerts et al 2007, Sato et al 2012. The combination of these two factors is such that, in soils that are not greatly disturbed, mean constant infiltration is greater than in soils where disturbance is extensive.…”