Atributos químicos do solo e a produtividade de grãos afetados pelo gesso agrícola com e sem irrigação

Abstract

Among the benefits of gypsum can cite, improving subsoil, generated by higher Ca, m % and reduction of depth of root crops. This study was conducted on an Oxisol in the city of Boa Vista do Padlock northwestern region of Rio Grande do Sul experiment in a completely randomized design with 5 replications. The treatments used in the study were different doses of gypsum (CaSO4.2H2O) at doses of 0,0; 2,0; 4;0 and 8,0 Mg ha-1 applied to the surface of the soils under different management as irrigation with the aid of center pivot. Each soil sample was stratified in 5 depths, these layers were 0-0.05, 0.05-0.10, 0.10-0.20, 0.20-0.40 and 0.40-0,60 m depth. The soil samples were taken at time zero (initial characterization), after 10 months and 18 months of application of the plaster surface. The soil nutrients evaluated were pH, P, K, Ca, Mg, Al, S and saturation in CTC. Also granulometric content of the soil such as clay as well as yield of corn and soybean compared using the Tukey test at 5% probability (p = 0.05). The results obtained in the study show that the aluminum saturation, Ca, Ca/CTC, Ca/Mg, CTC, S and base saturation were influenced by the addition of gypsum applied to surface. The contents of Al, Ca, Ca/CTC, Mg, Mg/CTC, Ca/Mg, S, pH, P and base saturation were influenced as to irrigation management and the time with the exception of Al the productivity of corn and soybean were not affected significantly by treatments, possibly shortly after application. The gypsum applied superficially, was an effective alternative for improving the chemical quality of the subsurface layer of an Oxisol managed under no-tillage system.