Rill and sheet soil erosion estimation in an area undergoing desertification in the Brazilian semi-arid region

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ORIGINAL ARTICLE

Rill and sheet soil erosion estimation in an area undergoing desertification in the Brazilian semi‑arid region Manuella Vieira Barbosa Neto1   · Maria do Socorro Bezerra de Araújo2 · José Coelho de Araújo Filho3 · Everardo Valadares de Sá Barretto Sampaio4 · Brivaldo Gomes de Almeida5 Received: 5 July 2020 / Accepted: 17 October 2020 © Springer Nature Switzerland AG 2020

Abstract Soil erosion is a serious world problem, especially in areas undergoing desertification. Rill and sheet erosions were estimated in one municipality of the largest desertification nucleus in the Brazilian semi-arid region. Measurements were made in plots located in combinations of the two main soil classes (Luvisol and Planosol, 58 and 40% of the municipal area) and the two predominant vegetation covers (sparse and open, 84 and 7% of the municipal area). The sparse vegetation has 320 plants ­ha−1 covering 25% of the soil surface and the open vegetation has 495 plants ­ha−1, covering 40% of the soil surface. Length, width, and depth of all rills were measured in the plots to calculate the soil losses. Sheet erosion was estimated assuming that the height of the soil close to the bases of trees and shrubs in relation to the soil surface away from these bases corresponded to the depth of the lost soil layer. Rill erosion was higher under the sparse vegetation than under the open vegetation: 400 versus 45 Mg ha−1. Sheet erosion did not differ among soils and covers (547–860 Mg ha−1). Soil loss in the municipality was 34 Tg and 24 Eg when extrapolating to the desertification nucleus. Erosion and low vegetation cover are cumulative reinforcing degradation drivers, leading to low crop and livestock productivity, poverty, and social vulnerability. Land use restriction is the main measure to reduce erosion, but it increases social problems. Keywords  Vegetation cover · Soil classes · Caatinga · Luvisol · Planosol

Introduction Soil erosion is a serious world problem (García-Ruiz et al. 2015; Santos et al. 2017a; Parsons 2019). It reduces the production potential of a large agricultural area, gradually corroding the superficial soil layer and carving rills and gullies

which can be many meters deep (Arekhi et al. 2012). Rill and gullies draw attention and their spread may be more easily prevented than the insidious slow sheet losses which may remain unnoticed in the short run. Both processes decrease the soil capacity to provide plants with nutrients since its nutrient richest superficial layer is lost and to provide plants 2



Maria do Socorro Bezerra de Araújo [email protected]

Departamento de Ciências Geográficas, Universidade Federal de Pernambuco/UFPE, Av. Ac. Hélio Ramos, s/n, Recife, PE 50740‑530, Brazil

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José Coelho de Araújo Filho [email protected]

Empresa Brasileira de Pesquisa Agropecuária-Embrapa Solos UEP, Av. Antônio Falcão, 402, Recife, PE 51020‑240, Brazil

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Departamento de Energia Nuclear, Universidade Federal de Pernambuco/UFPE, Av. Prof. Luiz Freire, 1000, Recife, PE 50740‑540, Brazil

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De