Qualidade física e química do solo em função do sistema de produção e da aplicação superficial de silicato e calcário em experimento de longa duração
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Data
2016-03-18
Autores
Ferrari Neto, Jayme [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A adoção do sistema plantio direto (SPD) foi um dos grandes avanços da agricultura brasileira, e, diversos sistemas de produção agrícola são empregados nesse sistema. Da mesma forma que no sistema convencional de manejo do solo, no SPD também existe a necessidade de aplicação de insumos, especialmente, materiais corretivos da acidez. Os objetivos foram avaliar a influência da aplicação superficial dos corretivos da acidez do solo e dos sistemas de produção nas características físicas e químicas, bem como nas frações da matéria orgânica do solo, nutrição e produtividade das culturas graníferas em região de inverno seco. Este projeto foi continuação de um experimento instalado no ano agrícola 2006/2007, na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas – UNESP, localizada no município de Botucatu (SP), e foi conduzido durante os anos agrícolas 2011/2012 e 2012/2013. As parcelas foram constituídas por quatro sistemas de produção (I. Sistema “Safra consorciada com Forrageira”; II. Sistema “Safra – safrinha”; III. Sistema “Safra – Pousio”; IV. Sistema “Safra – Adubo Verde/Planta de Cobertura”) e as subparcelas por duas fontes de corretivos de acidez aplicados em outubro de 2006 e 2011, e o tratamento controle (I – Correção com calcário dolomítico; II – Correção com silicato de cálcio e magnésio; III – Sem correção). O delineamento experimental utilizado foi em blocos casualizados, no esquema de parcelas subdivididas, com quatro repetições. Foram realizadas as seguintes avaliações: as frações da matéria orgânica do solo (MOS) aos 24 meses após a última aplicação dos corretivos, os atributos químicos do solo aos 12 e 24 meses após a última aplicação dos corretivos, os atributos físicos do solo aos 24 meses após a última aplicação dos corretivos, teores de macronutrientes e silício e produção de massa de matéria seca de parte aérea em todas as culturas, componentes da produção e produtividade das culturas graníferas. O uso de espécies do gênero Urochloa em rotação com culturas graníferas aumenta os valores do C mineralizável, C da biomassa microbiana do solo (CBMS), C orgânico particulado (COP), C orgânico associado aos minerais (COAM) e do C orgânico total (COT) na camada de 0 a 0,05 m do solo. Quanto aos corretivos da acidez, aos 24 meses após a última aplicação dos corretivos, nota-se que há mais C mineralizável e CBMS na camada de 0 a 0,05 m do solo, por consequência da calagem. Quanto aos atributos químicos do solo, no período entre 12 e 24 meses após a última aplicação dos corretivos ocorre máxima reação dos corretivos da acidez no solo, aumentando a saturação por bases até a profundidade de 0,40 m. A reação do silicato é mais rápida que a reação do calcário, sendo o silicato mais eficiente que o calcário, principalmente, com relação à disponibilização de P, além de aumentar a concentração de Si no solo. O uso de forrageiras na rotação de culturas (sistema safra-forrageira) melhora a microporosidade na camada de 0 a 0,05 m de profundidade e a estabilidade dos agregados na camada de 0,10 a 0,20 m do solo. Com relação aos corretivos da acidez do solo, do mesmo modo que constatado para à MOS, não há efeito negativo da aplicação dos corretivos da acidez do solo nos atributos físicos do mesmo. As produtividades do feijão, arroz e do trigo cultivado na entressafra do primeiro ano agrícola são superiores por consequência da aplicação do silicato. As culturas do feijão e arroz são mais produtivas quando cultivadas sobre a fitomassa de forrageiras (sistema safra-forrageira). A produtividade do arroz quando cultivado após o trigo é baixa, não sendo indicada a sucessão de cultivos entre essas culturas.
The adoption of the no-tillage system (NTS) was one of the great advances in Brazilian agriculture, and several crop systems are used in this system. As well as observed in conventional soil management in a NTS there is also the need for application of soil acidity amendments. The aims were to evaluate the influence of surface application of soil acidity amendments and crop systems in the physical and chemical attributes, as well as in the fractions of soil organic matter, nutrition and grain yield of the crops in dry winter region. The present study was conducted in 2011/2012 and 2012/2013 and it was a sequence of a long term study that had been conducted since 2006/2007 in the College of Agricultural Sciences – FCA/UNESP, in Botucatu-SP, Brazil. The experimental design was the complete randomized block with split plots and four replications. Main plots consisted of four cropping rotations (“Season-Forage”; “Season-off-season”; “Season-Fallow” and “Season-Green manure”) and subplots by two sources of soil acidity amendments (dolomitic lime, calcium/magnesium silicate) plus a control, with no soil acidity correction. The following evaluations were performed:soil organic matter (SOM) fractions at 24 months after the last application of soil acidity amendments, chemical soil properties at 12 and 24 months after the last application of soil acidity amendments, soil physical properties at 24 months after the last application of soil acidity amendments, macronutrients and silicon concentrations and shoot dry matter of all crops, yield components and grain yield of the cash crops. The use of Urochloa spp in rotation with cash crops increases the values of mineralizable C, soil microbial biomass C (CBMS), particulate organic carbon (POC), organic carbon associated with minerals (COAM) and total organic carbon (TOC) in the 0 to 0.05 m from the ground. At 24 months after the last application of the soil acidity amendments there are more mineralizable C and CBMS in the 0 to 0,05 m from the ground, as a consequence of the superficial liming. Between 12 and 24 months after the last application of the soil acidity amendments occurs maximum reaction of lime and silicate, increasing the base saturation to a depth of 0.40 m. The silicate reaction is faster than lime reaction, being silicate more efficient than lime, particularly in increase P availability, besides increase the Si concentration in the soil. The use of the forage crop rotation (Season- forage system) improves microporosity in the 0 to 0.05 m depth and stability of aggregates in the 0.10 to 0.20 m depth. Regarding the soil acidity amendments, as well as observed for the MOS, there are not negative effect as a consequence of the application of soil acidity amendments in the soil physical attributes. The grain yield of common bean, rice and wheat grown in the off season of the first year are higher as a consequence of the application of silicate. The grain yields of common bean and rice are higher when grown on the straw of forage (Season - forage). The grain yield of rice when grown after wheat is low and is not recommended the succession between these crops.
The adoption of the no-tillage system (NTS) was one of the great advances in Brazilian agriculture, and several crop systems are used in this system. As well as observed in conventional soil management in a NTS there is also the need for application of soil acidity amendments. The aims were to evaluate the influence of surface application of soil acidity amendments and crop systems in the physical and chemical attributes, as well as in the fractions of soil organic matter, nutrition and grain yield of the crops in dry winter region. The present study was conducted in 2011/2012 and 2012/2013 and it was a sequence of a long term study that had been conducted since 2006/2007 in the College of Agricultural Sciences – FCA/UNESP, in Botucatu-SP, Brazil. The experimental design was the complete randomized block with split plots and four replications. Main plots consisted of four cropping rotations (“Season-Forage”; “Season-off-season”; “Season-Fallow” and “Season-Green manure”) and subplots by two sources of soil acidity amendments (dolomitic lime, calcium/magnesium silicate) plus a control, with no soil acidity correction. The following evaluations were performed:soil organic matter (SOM) fractions at 24 months after the last application of soil acidity amendments, chemical soil properties at 12 and 24 months after the last application of soil acidity amendments, soil physical properties at 24 months after the last application of soil acidity amendments, macronutrients and silicon concentrations and shoot dry matter of all crops, yield components and grain yield of the cash crops. The use of Urochloa spp in rotation with cash crops increases the values of mineralizable C, soil microbial biomass C (CBMS), particulate organic carbon (POC), organic carbon associated with minerals (COAM) and total organic carbon (TOC) in the 0 to 0.05 m from the ground. At 24 months after the last application of the soil acidity amendments there are more mineralizable C and CBMS in the 0 to 0,05 m from the ground, as a consequence of the superficial liming. Between 12 and 24 months after the last application of the soil acidity amendments occurs maximum reaction of lime and silicate, increasing the base saturation to a depth of 0.40 m. The silicate reaction is faster than lime reaction, being silicate more efficient than lime, particularly in increase P availability, besides increase the Si concentration in the soil. The use of the forage crop rotation (Season- forage system) improves microporosity in the 0 to 0.05 m depth and stability of aggregates in the 0.10 to 0.20 m depth. Regarding the soil acidity amendments, as well as observed for the MOS, there are not negative effect as a consequence of the application of soil acidity amendments in the soil physical attributes. The grain yield of common bean, rice and wheat grown in the off season of the first year are higher as a consequence of the application of silicate. The grain yields of common bean and rice are higher when grown on the straw of forage (Season - forage). The grain yield of rice when grown after wheat is low and is not recommended the succession between these crops.
Descrição
Palavras-chave
Sistema plantio direto, Culturas anuais, Correção da acidez do solo, Carbono-orgânico, No tillage system, Annual crops, Correction of soil acidity, Organic carbon