An obvious but not-mentioned-as-often-as-you-might-expect place to savor greenhouse gasses is in a greenhouse, especially if you have brought cow manure into that greenhouse. Details of one such observation:
“Greenhouse gas emissions from an alkaline saline soil cultivated with maize (Zea mays l.) And amended with anaerobically digested cow manure: a greenhouse experiment“, J. Juárez-Rodríguez, F. Fernández-Luqueño, E. Conde, V. Reyes-Varela, F. Cervantes-Santiago, E. Botello-Alvarez, M. Cárdenas-Manríquez & L. Dendooven, Journal of Plant Nutrition, 35(4), 2012, Pages: 511-523. The authors are at several institutions in Mexico. The authors say:
“Sludge derived from cow manure anaerobically digested to produce biogas (methane; CH4) was applied to maize (Zea mays L.) cultivated in a nutrient-low, alkaline, saline soil with electrolytic conductivity 9.4 dS m−1 and pH 9.3…. Nitrous oxide (N2O) emission from unamended soil was -0.0004 μg nitrogen (N) kg−1 soil day−1 and similar from soil cultivated with maize (0.27 μg N kg−1 soil day−1). Application of sludge increased the N2O emission to 4.59 μg N kg−1 soil day−1, but cultivating this soil reduced it to 2.42 μg N kg−1 soil day−1.”
(Thanks to investigator Tom Gill for bringing this to our attention.)