Agricultural Land Degradation in Peru and Bolivia

Soil erosion is the most prominent evidence of soil degradation and is regarded as the main type of agricultural land degradation worldwide. The objective of this contribution is to assess soil degradation associated with agricultural lands in Peru and Bolivia. The assessment is mainly based on a recent soil erosion survey; maps describing soil erosion rates across 5 km grids for the years 1990, 2000, 2010, and 2020; and global observations of agricultural land areas. We observe that soil erosion rates in agricultural lands from Peru and Bolivia are steadily growing. We also observe that (1) the highest quantities of soil erosion are found in the Andean highlands and the largest areas of soil denudation in the Amazonian sections, and (2) there is a positive relation between erosion degree and soil organic carbon stock. The main drivers of soil erosion are the intensive agriculture production and fertilizer use that have increased in Peru and Bolivia. This land use intensification in both countries is also the driver of other land degradation factors such as soil salinization and soil pollution. The use of sewage (e.g., gray water) in urban and peri-urban agricultural areas increases the risk to soil health by inducing the dispersion of microplastics assisted by soil erosion. Overgrazing affects a large portion of the highlands from both countries. Very limited information of the extent of slash-and-burn fire agriculture exists; however, this practice is mostly observed in the Department of Santa Cruz (Bolivia). To prevent or minimize the pressure on soil resources associated with soil erosion or soil pollution, we highlight the need to support sustainable soil management practices and responsible use of fertilizers in agricultural land.