Sediment Catcher to Trap Coarse Organic Matter and Soil Particles Transported by Wind

Abstract

Wind can erode fertile topsoil and reduce soil fertility. Evaluating the effect of wind erosion on soil fertility is crucial to achieve sustainable agriculture in areas suffering from desertification caused by wind erosion. To estimate soil loss and associated soil nutrient loss by wind erosion, flux of coarse organic matter (COM) (defined here as free organic debris larger than 200 µm) and soil particles (defined as the other soil components) must be measured separately. This is because their modes of transport are different, and COM plays a prominent role in soil nutrient dynamics in some semiarid zones where COM accounts for a large percentage of the total soil carbon. Because the Big Spring Number Eight (BSNE) sampler can trap both COM and soil particles 0.05 m above the surface, we designed a sediment catcher, the Aeolian Materials Sampler (AMS), to trap these components below 0.05 m. This device can be manufactured easily at low cost. AMS performance was tested by wind tunnel experiments over a range of wind velocities typically observed in erosive storms and with six incident wind angles because the AMS is a buried-type sampler that is unable to rotate toward the wind. The trapping efficiency of the AMS for COM and soil particles was not 100%, but it can be calibrated easily using wind data. Therefore, we can estimate the mass flux of COM and soil particles and evaluate the effect of wind erosion on soil fertility using the AMS with the BSNE sampler.