Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2005
Publication Date: 11/6/2005
Citation: Miles, D.M., Owens, P.R., Rowe, D.E. 2005. Spatial variability of litter gas flux and nutrients within two commercial broiler houses at the end of a winter flock [abstract]. Agronomy Abstracts. 2005 CDROM.
Technical Abstract: For broiler growers, management practices that reduce gas emissions and/or that accurately quantify litter nutrient species promote environmental stewardship and economic viability. This research characterized the variability of litter gas flux and nutrients, specifically nitrogenous compounds, in two solid sidewall commercial broiler houses. Near the end of a winter flock, on day 45 of the growout, ammonia and nitrous oxide concentrations were measured using a photoacoustic multigas analyzer; these were used to estimate flux from the litter. The 146 m by 12.8 m houses were sampled on a grid at 5 m across the house and 12 m down the house (36 points). Eight additional samples were taken near the feeders and waterers (F/W). Litter was sampled at each site to determine litter pH, moisture, ammonium, nitrate, and total Kjeldahl nitrogen (TKN). Geostatistical contour plots indicate trends for ammonia flux were similar in each house as were flux levels; house one (H1) averaged 694 mg m-2 hr-1 and house two (H2) 644 mg m-2 hr-1. Both houses exhibited a region of greater ammonia flux near the cooling pads and diminished flux at the F/W locations. Nitrous oxide flux was 15.8 mg m-2 hr-1 in H1 and 31.5 mg m-2 hr-1 in H2; trends of slightly greater levels near the walls were similar between the houses. Litter ammonium content was less in the center of the houses with elevated areas near the walls and exhaust fans. Nitrate levels averaged approximately 100 mg/kg in both houses, with elevated levels at the F/W sites. The results indicate that bird activity and house structure are influential factors for litter gas flux and nutrient level. Consistent trends among measured parameters show that structurally equivalent houses can be sampled the same.