Influences of different surface doses of limestone with and without gypsum in the physical characteristics of a sandy soil

• Grant number: 18/09581-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2018
• End date: June 30, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Carlos Sergio Tiritan
• Grantee: Maik Sergio Lopes da Silva
• Host Institution: Faculdade de Ciências Agrárias. Universidade do Oeste Paulista (UNOESTE). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The sandy soils are characterized by low fertility, low CTC, low levels of phosphorus and potassium and in general this type of soil presents light texture, low water retention capacity associated with high percolation rates and infiltration of the same. The objective of this work is to evaluate the physical characteristics of the soil with different doses of limestone combined with and without gypsum in sandy soils. The experiment was conducted at the Experimental Farm of Universidade do Oeste Paulista (Unoeste) in Presidente Bernardes - SP, at 22º17'27 "S, 51º40'51" W and 385 m altitude. According to the Brazilian Soil Classification System (EMBRAPA, 2006), the soil of the experimental area is classified as Dystrophic Red Argisol, with smooth undulating relief. The experimental design will be performed in bands with subdivided plot, in a 4x2 factorial scheme, with three replications. The plots were composed of the following limestone doses (0, 2, 4 and 8 t ha-1) and the subplots with and without agricultural gypsum (0 and 4 t ha-1). Soil assessments: soil chemical analysis (0-10, 10-20, 20-30, 30-40, 40-60 cm). The soil physical analysis will be: Resistance to penetration and moisture, aggregate stability index, soil density, total porosity (macro and micro), clay dispersed in water, total clay, flocculation degree, soluble carbon and total organic carbon (TOC). The data will be submitted to analysis of variance and, in case of significant effect for limestone and gypsum doses, regression analysis (linear or polynomial) will be performed to verify the effect of limestone doses on the surface. In the case of a significant effect for the superficial gypsum doses, the data will be compared by the Tukey test (5%), using Sisvar software (FERREIRA, 2010). (AU)