An evaluation of wind erosion hazard in fallow lands of semiarid Aragon (NE Spain)

Abstract

Long fallowing (16-17 months), in the cereal-fallow rotation, may favour soil losses by wind erosion in agricultural soils of semiarid Aragon (NE Spain). With the objective of evaluating the risk of wind erosion in this area, soil losses for the most critical period of fallow (February-April) were estimated from a total of 67 fallow fields by using the Wind Erosion Equation (WEQ). All soils were medium-textured soils being the loam the most frequent textural class (45%). The CaCO3 content in the soil was higher than 200 g kg-1 in 90% of the fields. Mouldboard plough, chisel plough, and disk harrow were the main primary tillage tools used by farmers during fallow. Soil cover by crop residues was negligible (<1%) in 76% of the fields and only in 20% tilling was done perpendicularly to dominant wind direction. The highest erodibility values corresponded to soils with a sandy loam texture and traditionally tilled with mouldboard plough. Predicted wind erosion was high to very high in 30% of the fields (>20 Mg ha-1). The WEQ estimated erosion reductions to tolerable levels if reduced tillage, with chiseling as primary tillage, is adequately adopted in the dryland cereal production areas of semiarid Aragon.