LIME RATES AND METHODS OF APPLICATION FOR SOYBEANS GREW IN A SANDY LATOSOL

Abstract

Soil acidity correction aims to neutralize Al³⁺ and H⁺ and supply Ca and Mg for the development of crops, such as soybean. However, there is no consensus on the optimum lime rates and application methods for sandy soils, especially in no-till, given their increased susceptibility to leaching of water and nutrients as well as reduced capacity of soil colloids. Thus, the aim of this study was to compare the efficiency of lime rates and application methods and establish liming criteria for soybean production in a sandy Latosol in Northwestern Paraná. The experimental soil was a typical dystrophic Red Latosol of sandy texture. Treatments consisted of surface and incorporated application of lime to achieve 50, 60, 70, and 80% base saturation and an untreated control (without lime). Soybean was grown in undeformed soil columns. After 114 days, plants were evaluated for height, stem diameter, shoot fresh weight, and shoot dry weight. The soil was analyzed for pH H₂O, pH CaCl₂, Al³⁺, exchangeable calcium, exchangeable magnesium, available phosphorus and potassium. The liming criteria that resulted in maximum development of soybean crops in sandy soil were base saturation of 60%, pH H₂O of 6.1, 3.20 cmol_c kg⁻¹ calcium, and 1.89 cmol_c kg⁻¹ magnesium.