EFFECTS OF A DAIRY LOAFING LOT‐BUFFER STRIP ON STREAM WATER QUALITY¹

Abstract

A loafing or sacrifice lot is an area located outside of the free stall barn, where a dairy herd spends several hours per day. Sacrifice lots are usually denuded of vegetation and have high concentrations of manure and urine that can contribute significant amounts of sediment, nutrients, and pathogens to nearby surface waters. In this study, stream water quality impacted by direct runoff from a sacrifice lot was monitored for a period of 20 months. Ambient stream water quality was monitored by grab sampling upstream and downstream of the sacrifice lot. During runoff events, stream water quality downstream of the sacrifice lot was monitored with an automatic sampler. Laboratory analyses were conducted for total suspended solids and nutrients (nitrogen and phosphorus compounds). A grass filter strip (GFS) was installed as a buffer downslope of the sacrifice lot 10 months into the study period. The impact of the buffer strip on the standardized pollutant concentrations and loads was evaluated using the non‐parametric Wilcoxon test. The Wilcoxon test indicated that there was no significant difference (α= 0.05) in the standardized yield of sediment and dissolved pollutants before and after the GFS installation, except for phosphate‐phosphorus and filtered total phosphorus concentrations, and sediment‐bound total phosphorus and total kjeldahl nitrogen loads that decreased significantly. However, load decrease could have been partially caused by the smaller rainfall volumes after the GFS installation as compared to the existing condition.

Transport ofCryptosporidium parvumOocysts through Vegetated Buffer Strips and Estimated Filtration Efficiency

“…on May 10, 2018 by guest http://aem.asm.org/ microbial pathogens from animal agricultural operations to nearby surface water supplies (51). The assumption is that by placing a vegetated buffer of adequate width between livestock populations and adjacent surface water supplies, microorganisms that are shed in the feces or urine of livestock will be removed (strained or adsorbed) as they are transported via advective and dispersive processes through the vegetated buffer (10,12,15,32,59,60). In testing this assumption, we determined that a 100-cm-long vegetated buffer with 85 to 99% perennial fescue cover and under conditions involving a 5 to 20% slope, silty clay loam, loam, or sandy loam and precipitation rates of 1.5 or 4.0 ml/cm 2 /h, produced a 1.0-to 3.1-log 10 mean reduction in waterborne C. parvum oocysts (bovine genotype A) ( Table 6).…”

“…One strategy being advocated for minimizing the transport potential of C. parvum oocysts from animal manure to surface water is to place vegetated buffer strips between animal agricultural operations and vulnerable surface water supplies (10,12,15,32,38,51,59,60). Optimal design criteria for on-farm vegetated buffer strips currently do not exist for waterborne microbial contaminants.…”

SignificantEscherichia coliAttenuation by Vegetative Buffers on Annual Grasslands

“…Waterborne transport of microbial pathogens and indicators, and resulting public health risk, is governed by (i) processes that load a watershed with microbial pollutants, (ii) processes that attenuate or inactivate microbial pollutant load, and (iii) the efficiency of hydrologic transport processes which connect terrestrial pollutants to aquatic components of the watershed. One strategy for minimizing the transport of microbial pathogens and bacterial indicators from animal agricultural operations to surface water is to create vegetated buffer strips between animal manure sources and vulnerable surface water supplies (Young et al, 1980; Dillaha et al, 1989; Castelle et al, 1994; Younos et al, 1998; Schmitt et al, 1999; Dosskey, 2002). The attenuation efficiency of vegetative buffers varies by pollutant (e.g., sediment, nitrate) and depends on site specific factors such as runoff volume, soil properties, and buffer management (Castelle et al, 1994; Schmitt et al, 1999; Bharati et al, 2002; Bedard‐Haughn et al, 2004).…”

Efficacy of Vegetated Buffer Strips for Retaining Cryptosporidium parvum

“…vertebrate hosts, and to determine if land slope (%) coli (Young et al, 1980;Coyne et al, 1995;Younos et influences the ability of a buffer to retain oocysts. Entry et al, 2000;Rosen et al, 2000).…”