Aplicação de dejeto suíno e estrutura de um latossolo vermelho sob semeadura direta

Abstract

RESUMOObjetivou-se, neste trabalho, estimar o efeito da aplicação de doses crescentes de dejetos suínos, em atributos físicos do solo. O experimento localizado em Campos Novos, SC, foi conduzido num Latossolo Vermelho Distroférrico, no delineamento experimental em blocos casualizados, com quatro repetições, com os tratamentos: testemunha (0); adubo solúvel (AS); combinação dejeto e adubo solúvel (DS); dejeto líquido suíno aplicado nas doses de 50, 100 e 200 m 3 ha -1 . Desde 2001 foi cultivado milho e aveia preta, sob sistema de semeadura direta. A amostragem do solo foi realizada em janeiro de 2006, nas camadas de 0-5; 5-10; 10-20 cm de profundidade, para determinação de carbono orgânico, densidade, estabilidade de agregados, macroporos, microporos e porosidade total. A aplicação de dejeto suíno nas doses de 50 e 100 m 3 ha -1 , reduziu a estabilidade de agregados do solo em relação à testemunha sem adubação. Os demais atributos físicos do solo e o teor de C orgânico não foram modificados pelos tratamentos, indicando que o uso agrícola do dejeto suíno, nas condições estudadas, mantém a qualidade física do solo. Termos para indexação:Adubação orgânica, descarte de dejetos, estabilidade de agregados, esterco. ABSTRACTThe objective of this study was to assess the effects of crescent doses of pig slurry on physical soil properties. The experiment is carried out in Campos Novos, SC, southern Brazil, on a red distroferric latosol, with a completely random blocks experimental design and four replicates, with the following treatments: control (0); soluble fertilizer (SF); combination of pig slurry and soluble fertilizer (SS); pig slurry applications of 50, 100 and 200 m 3 ha -1 . Since 2001, maize and black-oat were cultivated under no tillage soil management. Soil samples were collected in January 2006, from 0-5; 5-10; 10-20 cm deep, to analyze organic carbon, soil density, aggregate stability, macro, micro and total porosity. The application of 50 and 100 m 3 ha -1 of pig slurry decreased soil aggregate stability, in relation to the control treatment with no fertilization. The other physical properties and organic carbon contents had no effect on the treatments, demonstrating the pig slurry application under these tested conditions maintains the soil physical quality. Index terms: INTRODUÇÃOO avanço tecnológico na produção de suínos despertou interesse crescente em confinar animais em todas as fases do ciclo produtivo, aumentando a produtividade por unidade de área e de tempo. Essa concentração de animais trouxe como consequência alta produção de dejetos, sendo um desafio seu adequado aproveitamento para evitar problemas ambientais (Oliveira, 1993). Um dos destinos desses resíduos consiste na adição ao solo como fertilizante o que pode trazer benefícios às culturas pela adição de nutrientes e matéria orgânica (Scherer et al., 1995).A aplicação de resíduos orgânicos no solo é uma das formas de repor os elementos extraídos pelas culturas, complementando ou substituindo os fertilizantes minerais recomendados nos progra...

Effects of pig slurry application on soil physical and chemical properties and glyphosate mobility

“…However, differences among treatments were observed for water retention in pores less than 50 µm in diameter, saturated hydraulic conductivity, and arithmetic mean diameter of air-dried aggregates (Table 3). Similar results have been reported in other studies comparing physical characteristics of plots to which different rates of pig slurry were applied (Veiga et al, 2008;Arruda et al, 2010;Veiga et al, 2012).…”

“…Bulk density is lower in the 0.00-0.05 m layer, increasing with depth. Similar results were obtained by Arruda et al (2010), who also examined the effect of pig slurry application on soil physical properties. These authors concluded that the lower density in surface layers could be related to the organic matter introduced when organic residues are applied, which may improve the degree of aggregation and reduce the soil mass by lowering specific density, and may even fill soil pores.…”

“…For this property, differences were also observed in the second layer sampled, and its values increase up to 100 m 3 ha -1 yr -1 of pig slurry application and fall at the highest rate of application. Different results were reported by Arruda et al (2010), who found that pig slurry applications at rates of 50 and 100 m 3 ha -1 reduced soil aggregate stability in relation to fertilized control plots, and that there were no changes in other soil physical properties, showing that pig slurry use in agriculture maintained soil physical quality under the conditions studied.…”

Changes in a Rhodic Hapludox under no-tillage and urban waste compost in the northwest of Rio Grande do Sul, Brazil

“…A reduction of the amounts of water-stable aggregates retained on the sieve of 8.00-4.76 mm for UWC rates above 50 m 3 ha -1 (second year of assessment) was also observed with application of high rates of other organic sources, such as alkaline residues from the pulp and paper industry (Medeiros et al, 2009), pig slurry (Arruda et al, 2010), vinasse from sugarcane (Passarin et al, 2007), and turkey litter (Costa et al, 2008;Pinto et al,. 2012).…”

“…The authors reported increased aggregation with 2.6 Mg ha -1 and dispersing effect of the chemical elements when higher rates were applied (10.5 Mg ha -1 ). Arruda et al (2010) observed that the aggregate stability in an Oxisol was higher in the control treatment (GMD = 6.1 mm) and decreased with the application of 50 and 100 m 3 ha -1 of pig slurry (GMD = 5.7 mm). Also, Oades (1984) observed that organic acids can exert direct dispersing effects or aggregate complexation by cations such as Al 3+ .…”