Is green waste fertilization in agriculture an important source of VOC? A field study based on PTR-Qi-TOF-MS and eddy covariance

Agriculture is a potentially large yet poorly characterized source of volatile organic compounds (VOCs). Crops are the largest and most well-known source of VOCs from agriculture. Agricultural management practices, and especially organic fertilization is an especially unknown source of VOCs. A 3-week field campaign was conducted in September 2023 in Saclay, France, 30 km southwest of Paris. We investigated VOC fluxes over a mustard and moha field (cover crops) by eddy covariance using a PTR-Qi-TOF-MS. Green waste was applied during the second week of measurements.

We detected over a hundred VOCs with fluxes 3 times above the detection limit, and found that: 1) Oxygenated VOCs and monoterpenes are the most emitted compound groups. 2) High fluxes of methanol, ethanol, acetone, and acetaldehyde were detected after organic fertilizer spread. 3) A relatively strong sesquiterpene emission was observed after fertilization and was not previously reported. Our results provide new insights into VOC emissions from cover crops and green waste application.