Implications of seasonal and daily variation on methane and ammonia emissions from naturally ventilated dairy cattle barns in a Mediterranean climate: A two-year study.

Seasonal and daily variations of gaseous emissions from naturally ventilated dairy cattle barns are important figures for the establishment of effective and specific mitigation plans. The present study aimed to measure methane (CH4) and ammonia (NH3) emissions in three naturally ventilated dairy cattle barns covering the four seasons for two consecutive years. In each barn, air samples from five indoor locations were drawn by a multipoint sampler to a photoacoustic infrared multigas monitor, along with temperature and relative humidity. Milk production data were also recorded. Results showed seasonal differences for CH4 and NH3 emissions in the three barns with no clear trends within years. Globally, diel CH4 emissions increased in the daytime with high intra-hour variability. The average hourly CH4 emissions (g h-1livestock unit-1 (LU)) varied from 8.1 to 11.2 and 6.2 to 20.3 in the dairy barn 1, from 10.1 to 31.4 and 10.9 to 22.8 in the dairy barn 2, and from 1.5 to 8.2 and 13.1 to 22.1 in the dairy barn 3, respectively, in years 1 and 2. Diel NH3 emissions highly varied within hours and increased in the daytime. The average hourly NH3 emissions (g h-1 LU-1) varied from 0.78 to 1.56 and 0.50 to 1.38 in the dairy barn 1, from 1.04 to 3.40 and from 0.93 to 1.98 in the dairy barn 2, from 0.66 to 1.32 and from 1.67 to 1.73 in the dairy barn 3, respectively, in years 1 and 2. Moreover, the emission factors of CH4 and NH3 were 309.5 and 30.6 (g day-1 LU-1), respectively, for naturally ventilated dairy cattle barns. Overall, this study provided a detailed characterization of seasonal and daily gaseous emissions variations highlighting the need for future longitudinal emission studies and identifying an opportunity to better adequate the existing mitigation strategies according to season and daytime.

Ammonia and greenhouse emissions from cow's excreta are affected by feeding system, stage of lactation and sampling time.

Decomposition of dairy cows' excreta on housing floor leads to ammonia and greenhouse gases production, yet factors affecting total emissions have not been fully disclosed. This work aimed to assess the impact of lactation stage, feeding system and sampling time on gaseous emission potential of cow's faeces and urine in laboratory chambers systems. Individual faeces and urine were collected from two groups of four cows, at peak and post peak lactation, from three commercial farms with distinct feeding systems: total mixed ration (TMR), total mixed ration plus concentrate at robot (TMR + robot), and total mixed ration plus concentrate in automatic feeders (TMR + AF). Samples were collected before a.m. (T8h), at middle day (T12h), and before p.m. (T17h) milking. In a laboratory chambers system, faeces and urine were mixed in a ratio of 1.7:1, and ammonia and greenhouse gases emissions were monitored during 48-h. Cumulative N-N2O emissions were the highest in TMR + robot system, post peak cows and sampling time T17h. An interaction between stage of lactation and sampling time was detected for N-NH3 and N-N2O (g/kg organic soluble N) emissions. Post peak cows also produced the highest cumulative N-NH3 emissions. Overall results contribute for the identification of specific on-farm strategies to reduce gaseous emissions from cows' excreta.

Ammonia and greenhouse gas emissions following the application of clinoptilolite on the litter of a breeding hen house.

The husbandry of chicken for meat generates high levels of gases, being a serious problem for the health of birds and workers as well as for the environment. The aim of the present study was to assess the effect of clinoptilolite as litter additive on the concentrations and emissions of ammonia (NH3), nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) from a breeding hen house under Mediterranean climate conditions. Two similar breeding hen houses were selected, and one house was assigned as control whereas the other house was treated with clinoptilolite as a litter additive. Data were collected during the winter season, in two occasions, first between 26 November and 18 December 2017 and second from 1 to 20 February 2018. Results showed that the application of clinoptilolite on the litter of a breeding hen house reduces the NH3 and N2O losses in 28 and 34%, respectively, but appears to have no effect on CO2 losses. In addition, the in-house CH4 concentrations were below the detection limits.

Dataset on ammonia, nitrous oxide, methane, and carbon dioxide fluxes from two soils fertilized amended with treated and non-treated cattle slurry.

The current data article presents a set of fluxes of ammonia (NH3), nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) measured from two different soils under a Mediterranean double-cropping system (oat in autumn/winter followed by maize in spring/summer). The two soils were fertilized using four different treatments: (i) Injection of raw cattle slurry (100 mm depth), (ii) application of raw cattle slurry followed by soil incorporation (20 mm depth), (iii) band application of acidified (pH=5.5) cattle slurry followed by soil incorporation (20 mm depth), and (iv) band application of acidified (pH=5.5) cattle slurry without soil incorporation. A non-amended soil was also considered as control treatment. The data presented here were obtained over a three years experiment between 2012 and 2015. Fluxes were measured in a period between slurry applications to soil (before plant seeding) till crop harvest. The data presented here are supporting the research article "Band application of acidified slurry as an alternative to slurry injection in a Mediterranean double-cropping system: Agronomic effect and gaseous emissions" (Fangueiro et al., 2018).