Ammonia and nitrous oxide emissions from broiler houses with downtime windrowed litter

Authors: Ro, Kyoung; Moore, Philip; Szogi, Ariel; Millner, Patricia

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2017
Publication Date: 5/18/2017
Citation: Ro, K.S., Moore Jr, P.A., Szogi, A.A., Millner, P.D. 2017. Ammonia and nitrous oxide emissions from broiler houses with downtime windrowed litter. Journal of Environmental Quality. 46:498-504.

Interpretive Summary: An emerging poultry manure management practice is in house windrowing to disinfect the litter. With this practice, growers windrow the litter in broiler houses between flocks, usually for 2 weeks. This results in high litter temperatures that can reduce pathogens in the litter. However, this practice is likely to increase emissions of ammonia and nitrous oxide from the litter. The objective of this study was to quantitatively compare ammonia and nitrous oxide emissions from bird houses with and without in-house windrowing. Two separate commercial broiler houses (with and without in house windrowing) with similar flock size of (25-30,700 birds) and operation were used to compare the gas emissions repeated in time. Gas emission measurements were conducted continuously and simultaneously for both control house (without windrowing) and the house with windrowing during the same production periods. The impact of downtime litter windrowing management on pathogen reduction was inconclusive because of very low recovery of test microorganisms with respect to the control. Both ammonia and nitrous oxide emissions from the in-house windrowing house were higher than that from control house. These higher gas emission rates from the windrowing house were attributed to higher litter temperatures. The gas emission from the downtime litter management was attributed to 31 and 16% of the total ammonia and nitrous oxide emissions per bird, respectively.

Technical Abstract: An emerging poultry manure management practice is in house windrowing to disinfect the litter. With this practice, growers windrow the litter in broiler houses between flocks, usually for 2 weeks. This results in high litter temperatures that can reduce pathogens in the litter. However, this practice is likely to increase emissions of ammonia (NH3) and nitrous oxide (N2O) from the litter. The objective of this study was to quantitatively compare NH3 and N2O emissions from bird houses with and without in-house windrowing. Two separate commercial broiler houses (with and without in house windrowing) with similar flock size of (25-30,700 birds) and operation were used to compare the NH3 and N2O emissions repeated in time. Gas emission measurements were conducted continuously and simultaneously for both control house (without windrowing) and the house with windrowing during the same production periods. The house emission rates were calculated by multiplying the hourly-mean gas concentrations and the ventilation rates. The windrowed litter temperature was significantly higher than that of the control litter. The impact of downtime windrowing litter on pathogen reduction was inconclusive because both E. coli and Salmonella spp. were recovered sporadically and at very low concentrations of 0.8-1. MPN/g from control litter. These microbes were not even recovered sporadically from the windrowed litter. The windrowing house emissions of NH3 were 26.2 and 16.6 kilogram per day per house (kg d-1 house-1), while for the control house were 14.6 and 12.8 kg d-1 house-1. The N2O emissions from the windrowing house (0.92 and 2.38 kg d-1 house-1) were also higher than those from the control house (0.10 and 0.51 kg d-1 house-1). These higher gas emission rates from the windrowing house were attributed to higher litter temperatures. The total NH3 and N2O emissions from broiler houses practicing windrowing litter management were estimated to be 31.2 and 3.95 gram per bird (g bird-1), respectively.