Increasing doses of agricultural gypsum, aggregate stability and organic carbon in Cerrado Latosol under Coffee crop

Abstract

The management of perennial crops could encourage the improvement of the soil, making it more productive, provided that appropriate agronomic practices are adopted. In order to evaluate the structure of a Cerrado Latosol subjected to soil management that adopts the use of high doses of gypsum and brachiaria on the coffee plants interrow, we studied the stability of aggregates and total soil organic carbon after two years of deployment of coffee. Soil samples were collected at 5 and 15 cm of depth in the crop coffee row located in the Alto São Francisco region, Minas Gerais states. The treatments were: G-0, no gypsum on the row, G-7, 7.0 Mg ha–1 of gypsum distributed in the coffee row, G-28, 28 Mg ha–1 of gypsum distributed in the coffee row, G-56, 56 Mg ha–1 of gypsum distributed in the row, CV-0, conventional management without gypsum CV-0 conventional tillage without gypsum in the row and grasses between row Brachiaria sp. between rows of coffee plants. Chemical analyzes were performed to determine the cations K+, Ca+2, Mg+2, P, and Al+3, total organic carbon and physical analysis of soil aggregate stability. It was determined the mean weight diameter and geometric mean diameter of aggregates retained on sieves with diameters ranging from 4 to 0.105 mm. All treatments were found more than 90% of aggregates with a diameter >2 mm suggesting that the management adopted a positive influence soil aggregate stability. The total organic carbon were positive and significantly correlated with aggregation. The dose of gypsum 7 t ha–1 positively altered the aggregation of soil specially in the superficial layer (15 cm).