Salinization in Peruvian North Coast Soils: Case Study in San Pedro de Lloc

Abstract

Soils in San Pedro de Lloc have been used for agriculture since pre-Columbian times. Rice crops are still currently irrigated by flooding using water from the Jequetepeque River. Therefore, soil degradation by salinization is a permanent threat to soil fertility and production. This chapter presents the results of studies carried out in the 1960s, 70s, and 80s, as well as recent works on surface water, underground water, and soil quality monitoring. Physicochemical parameters, such as electrical conductivity, pH, total dissolved solids, hardness, chemical oxygen demand, as well as nitrate, sulfate, phosphate, and chloride concentrations were measured in both surface water and underground water. Organic matter, texture class, and SAR were additionally measured in the soil samples. Electrical conductivity was spatially represented for easy comparison. The isopleth curves of the water table and a map showing the expansion of the agricultural area are included. It is concluded that the increase in the volume of water used for irrigation after the construction of the Gallito Ciego dam has raised the water table and soil salinization has been stimulated. This has led to the abandonment of cultivation fields and groundwater wells between 2003 and 2019 due to intense salinization.