Differences in the sediment composition of wind eroded sandy soils before and after fertilization with poultry manure

Abstract

Wind erosion is known to be a gradual process of soil degradation on arable lands. Poultry manure fertilization is a common practice to improve physical, chemical and biological soil properties, and is thus an essential part to maintain soil fertility. Shortly after incorporation, poultry manure and soil particles are loosely adjacent without any bonding. This supposedly affects the susceptibility of soils to wind erosion and influence the physical and chemical composition of the wind-eroded sediment. Wind tunnel experiments were conducted with three wind speeds (8, 11, 14 m s−1) and four sandy soils, each fertilized with poultry manure in a common rate of 6 t ha−1. Incorporation of manure in the soils changed the particulate organic matter (POM) composition resulting in increased median particle diameters, carbon contents and hydrophobicity. Wind erosion caused a preferred release of manure particles already at wind speeds close above the threshold of 7 m s−1 with the greatest sorting effects in size, shape, and density of the particles. Thus, wind erosion immediately leads to losses of the added organic material. At higher wind speeds the sediment composition rather corresponds to the entire soil or soil-manure mixtures. Depending on the wind speed and total soil loss, potential manure losses between 101 and 854 kg ha−1 were accounted, which are 1.7–14% of the fertilization rate. The results indicate a risk of substantial loss or redistribution of poultry manure by wind erosion immediately after incorporation.