Atributos do Solo e Acúmulo de Carbono na Integração Lavoura-Pecuária em Sistema Plantio Direto

Abstract

resumo em sistemas de produção como a integração lavoura-pecuária (ilP) em sistema plantio direto (sPd) têm sido observadas melhorias nos atributos químicos, físicos e biológicos do solo. sendo assim, objetivou-se avaliar as alterações nos atributos químicos e físicos do solo e o acúmulo de carbono (C) num Latossolo Vermelho distrófico típico argiloso utilizado em sistema de ilP em sPd com irrigação, no cerrado. o delineamento experimental utilizado foi de blocos casualizados, com quatro repetições. os tratamentos foram dispostos em parcelas subdivididas no tempo, e as parcelas experimentais foram compostas pelas culturas do milho e do sorgo forrageiro cultivadas exclusivamente ou consorciadas com as espécies forrageiras Urochloa brizantha cv. Xaraés e Megathyrsus maximum cv. tanzânia para ensilagem; pelas espécies forrageiras no período de entressafra; e pela cultura da soja em sucessão. ForamRecebido para publicação em 13 de maio de 2014 e aprovado em 29 de outubro de 2014.

Autumn Maize Intercropped with Tropical Forages: Crop Residues, Nutrient Cycling, Subsequent Soybean and Soil Quality

“…This behavior was also observed by several other authors in the same study region, who stated improvements in this soil property by crop rotation, in particular by intercropping of maize with tropical forages and subsequent soybean (Chioderoli et al, 2012;Mendonça et al, 2013;Costa et al, 2015). The values of MA, MI, TP and BD reported by these authors were very similar to those in this study, under the same soil and climatic conditions.…”

“…Thus, for tropical soils with irrigated crops, this threshold of 0.10 m 3 m -3 may not be the real limiting value for agricultural production. The succession maize -soybean improved soil MA, regardless of the use of forage -maize intercrops (Mendonça et al, 2013;Costa et al, 2015), which is the crop rotation system indicated for NTS in the Cerrado region to improve this soil physical property.…”

“…By the decomposition process of the residual plant biomass, the soil was supplied with nutrients, stimulating the biological activity and leading to changes in fertility (Costa et al, 2015). The forages and sowing methods did not influence the macro-(MA), micro-(MI), and total porosity (TP), and bulk density (BD) in the 0.0-0.2 m soil layer (Table 6).…”

“…Increase in MA values after soybean (Table 6) probably occurred because the soil was exploited by different root systems (grasses and legumes), which, after decomposition of the root mass, contribute to the formation of an architecture of permanent pores, resulting in greater MA of the soil (Costa et al, 2015). This behavior was also observed by several other authors in the same study region, who stated improvements in this soil property by crop rotation, in particular by intercropping of maize with tropical forages and subsequent soybean (Chioderoli et al, 2012;Mendonça et al, 2013;Costa et al, 2015).…”

“…The inclusion of tropical grasses in intercropping, rotation and/or sequence with grain crops in agricultural systems such as NTS represents a contribution to the maintenance and even improvements of the chemical and physical soil properties (Chioderoli et al, 2012;Mendonça et al, 2013;Costa et al, 2015). Mainly the inclusion of species with different root systems and plant residues with different C/N and lignin/N rates can influence the rates of decomposition and nutrient cycling.…”