Quantification of water, soil and nutrient losses in the Farinha river basin, Carolina - MA, in the Cerrado biome

Abstract

Natural resources, such as soil and water, play a crucial role in sustaining life on Earth. When used appropriately, these resources can mitigate environmental impacts. However, inadequate soil management practices can result in negative effects, such as the intensification of erosion processes and significant losses of soil, water and nutrients essential for plant growth. Thus, considering that the Farinha River basin - MA is located in the Cerrado biome and has a large part of its area occupied by highly erodible soils, the aim was to quantify water, soil and nutrient losses using a rainfall simulator. The experimental design adopted was entirely randomised (DIC), in a bifactorial scheme with 5 replications. Factor 1 considered two types of soil management systems (Anthropised Area and Non-Anthropised Area), while factor 2 involved three simulated rainfall intensities (80mm.h-¹, 110mm.h-¹ and 130mm.h-¹). The response variables assessed were losses of water, soil and nutrients and organic matter.The averages were subjected to analysis of variance and, if significant, the Tukey test was applied at 5% probability using Past 4.03 software. The results indicated significant losses of soil, water and nutrients associated with both the soil management system and the rainfall intensities, as well as making it possible to quantify the nutrients lost in runoff water on site. The conclusion is that the combination of inadequate soil management practices and intense rainfall can exacerbate erosion processes and the leaching of macro and micronutrients, resulting in an increasing need to incorporate fertilisers and correctives into agroforestry activities. Furthermore, it is important to emphasise that water erosion also contributes to an increase in soil and nutrient loss, which can lead to adverse environmental impacts, such as contamination of water resources and degradation of soil quality.