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Physical and chemical quality of the soil as a function of the crop system and surface application of silicate and lime in a long term experiment

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Author(s):
Jayme Ferrari Neto
Total Authors: 1
Document type: Doctoral Thesis
Press: Botucatu. 2016-05-02.
Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agronômicas. Botucatu
Defense date:
Advisor: Carlos Alexandre Costa Crusciol
Abstract

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. (AU)

FAPESP's process: 11/10566-6 - PHYSICAL AND CHEMICAL CHANGES AND FRACTIONATION OF SOIL ORGANIC MATTER AS FUNCTION AS CROP SYSTEM AND SUPERFICIAL LIMING AND SILICATE APPLICATION
Grantee:Jayme Ferrari Neto
Support Opportunities: Scholarships in Brazil - Doctorate