EFFECTS OF BEDDING TYPE AND WITHIN-PEN LOCATION ON FEEDLOT RUNOFF

Abstract

This two-year study examined the effects of two types of bedding materials (straw and wood chips) and twowithin-pen locations (bedding pack and pen floor) on various feedlot runoff parameters in southern Alberta, Canada, usinga rainfall simulator. Bedding type affected antecedent factors and hydrological parameters differently by year. Bedding packlocations absorbed 23.5% to 32.9% more moisture, had about 8 cm greater manure depths, slopes between 2.1% and 5.1%steeper, and surfaces that were 2.6% to 5.7% rougher than pen floor locations. Pen floor locations had clod bulk densitiesthat were 0.83 Mg m-3 greater than bedding pack locations in 1998. However, the effect of bedding packs on these propertiesdepended on the amount of bedding added, which depended on feedlot conditions. Runoff began sooner from pen floor thanfrom bedding pack locations. Once runoff started, the amount and type of bedding material, length of time since fresh beddingwas added, and within-pen location affected the time for specific runoff volumes. For example, in 1998, 6 L of runoff werecollected about 3 min faster from wood chips than from straw bedding and about 7 min faster from the pen floor than fromthe bedding pack. Runoff coefficients increased during the simulation events and occasionally exceeded rainfall applicationrate depending on whether or not water in depression storage was released. Treatment effects were dependent on year of study,and were inconsistent. Thus, further study is warranted regarding the effects of bedding type on feedlot runoff.