Direct Measurement of Greenhouse Gas Emission Rates From Manure Management in Different Livestock Production Systems in Cameroon

ABSTRACT Direct measurements of greenhouse gas emissions from the increasingly intensified African livestock production are important to assess locally available mitigation strategies. As such, measurements were conducted from March to June using static flux chambers to quantify the emission rates of CH 4 , N 2 O, and CO 2 from manure in poultry and pig production systems in Cameroon. Emissions were measured from two layer barns, two pig facilities, six broiler farms, and one farm with Brahman birds. Mean emission factors inside two layer barns were 0.06–0.21 and 602–958 mg animal −1 h −1 for CH 4 and CO 2, respectively, and 21–112 µg animal −1 h −1 for N 2 O. Mean emission factors inside four broiler barns with wood shavings as bedding material were 0.31–1.22 and 355–1884 mg animal −1 h −1 for CH 4 and CO 2 , respectively, and 2.33–1052 µg animal −1 h −1 for N 2 O. Broiler N 2 O emissions were 971.38 ± 250.23 and 26.14 ± 30.27 µg animal −1 h −1 from manure underneath a meshed floor barn and a shelter with bare soil, respectively. Emissions from a storage tank with wastewater from a piggery were 8.30 ± 7.36 and 40.41 ± 5.54 mg m −2 min −1 for CH 4 and CO 2 , respectively, and 2.80 ± 1.67 µg m −2 min −1 for N 2 O. Mean emissions from two outdoor storages of a mixture of poultry and pig manure were 0.76–0.9 and 69–136 mg m −2 min −1 for CH 4 and CO 2 , respectively, and 10–15 µg m −2 min −1 for N 2 O. Emissions depended highly on manure production and management systems. CH 4 emissions were lower from poultry compared to pig manure. Younger layers emitted higher CH 4 compared to older layer hens. CH 4 emissions were higher from slurry compared to solid manure, whereas N 2 O emissions were higher from solid compared to slurry manure storages. These findings indicate that mitigation strategies for greenhouse gas emissions should depend not only on the type of gases and manure management systems but also on the animal types and their ages.