TOLERANCE OF SOIL LOSS BY EROSION IN THE WESTERN MESOREGION OF MARANHÃO

Abstract

The growing technological advance in agriculture, verified through the introduction of machines, fertilizers, new cultivars, and expansion of agricultural frontiers, has provided, in general, an increase in the average yield of crops due to the rational management of the soil-climate-plant system. However, as the soil is managed without adopting conservationist practices, imbalances and instability occur, constituting serious problems such as desertification, salinization, soil erosion, etc. Thus, this study aimed to determine the soil loss tolerance by erosion in the western mesoregion of Maranhão. The methods used to determine tolerance used effective depth (h), textural ratio (r), textural ratio and clay content in the A horizon, organic matter, and permeability, where the equations for each method were: T= h. r. 1000-1 (Method I); T = h. ra. 1000-1 (Method II) and T = h. ra. m. P. 1000-1 (Method III). The highest soil loss tolerance values were identified in method I (1.95 t ha-1 yr-1), then method III (0.76 t ha-1 yr-1), and finally, method II (0.67 t ha-1 yr-1), observing soil loss tolerance values differed about the method used.