Soil erosion by piping in irrigated fields

This paper reports on soil losses from pipe networks in irrigated fields in the Ebro Basin, Spain. The factors encouraging the evolution of pipes are the number of irrigations, the type of crop, the existence of more impervious layers in the C soil horizon and the hydraulic gradient. The water used for irrigation is a low-salinity water, frequently unsaturated in calcite and dolomite. It therefore dissolves some of the soil carbonate and takes calcium from the exchange complex, thus contributing to soil dispersion and erosion. From monitoring the hydromorphological behaviour of two pipe networks, soil loss from the affected plots is estimated at 3 t ha−1 yr−1. The evolution of piping causes important losses of soil and water and can lead to the abandonment of farm land.