Aplicação de blends de calcários em plantio direto na cultura de milho após 3 anos da calagem

Abstract

Lime application can be one way to control and correct soil acidity, as well as interfering with soil chemical attributes, as well as corn cultivation, which needs certain levels of Ca2+ and Mg2+ for good development. The work was carried out in the municipality of Sinop, state of Mato Grosso, at an altitude of 384 meters and coordinates 12°01'14.8” south latitude and 55°30'12.9” west latitude of Greenwich, with a predominantly tropical climate ( AW), which its average annual temperature is greater than 24° C and its rainfall exceeds 1,500 mm. The soil, according to the classification in the Brazilian Soil Classification System (Embrapa 2018), is a Dystrophic Red-Yellow Lastosol (LVvAd) with a clayey texture. The work was carried out on the second crop corn, which evaluated the chemical attributes of the soil and the productive factors of the corn. The treatments comprised doses of calcitic and dolomitic limestone, which were applied in three different granulometries, which aimed at base saturation from 75 to 150%, which were applied manually and by haul, and treatment 13 received the two types of limestone, one superficially and the other incorporated through a plow harrow. After 33 months, the values of soil chemical attributes and productivity factors of corn second crop were determined. In soil chemical attributes, several treatments still showed significant variables in Ca+2 content, base saturation, Ca:Mg ratio and pH, treatment 11, which received a calcitic limestone dosage of 12.34 t ha-1 was one of the best values. For corn second crop, it obtained values of up to 13 bags more than the control treatment, showing that the effects of liming caused an increase in productivity. Even after 3 cultivations, it was observed that there are still limestone interactions in the soil, showing that, when limestone is applied, it lasts for many months with its residual effect.