Hao Xiying, Chang Chi, Larney Francis J
Agriculture and Agri-Food Canada, Lethbridge Research Centre, P.O. Box 3000, Lethbridge, AB, Canada T1J 4B1.
J Environ Qual. 2004 Jan-Feb;33(1):37-44. doi: 10.2134/jeq2004.3700.
Carbon and N losses reduce the agronomic value of compost and contribute to greenhouse gas (GHG) emissions. This study investigated GHG emissions during composting of straw-bedded manure (SBM) and wood chip-bedded manure (WBM). For SBM, dry matter (DM) loss was 301 kg Mg(-1), total carbon (TC) loss was 174 kg Mg(-1), and total nitrogen (TN) loss was 8.3 kg Mg(-1). These correspond to 30.1% of initial DM, 52.8% of initial TC, and 41.6% of initial TN. For WBM, DM loss was 268 kg Mg(-1), TC loss was 154 kg Mg(-1), and TN loss was 1.40 kg Mg(-1), corresponding to 26.5, 34.5, and 11.8% of initial amounts. Most C was lost as CO2 with CH4 accounting for <6%. However, the net contribution to greenhouse gas emissions was greater for CH4 since it is 21 times more effective at trapping heat than CO2. Nitrous oxide (N2O) emissions were 0.077 kg N Mg(-1) for SBM and 0.084 kg N Mg(-1) for WBM, accounting for 1 to 6% of total N loss. Total GHG emissions as CO2-C equivalent were not significantly different between SBM (368.4 +/- 18.5 kg Mg(-1)) and WBM (349.2 +/- 24.3 kg Mg(-1)). However, emission of 368.4 kg C Mg(-1) (CO2-C equivalent) was greater than the initial TC content (330.5 kg Mg(-1)) of SBM, raising the question of the net benefits of composting on C sequestration. Further study is needed to evaluate the impact of composting on overall GHG emissions and C sequestration and to fully investigate livestock manure management options.
碳和氮的损失降低了堆肥的农艺价值，并导致温室气体（GHG）排放。本研究调查了秸秆垫料粪便（SBM）和木屑垫料粪便（WBM）堆肥过程中的温室气体排放情况。对于SBM，干物质（DM）损失为301 kg Mg⁻¹，总碳（TC）损失为174 kg Mg⁻¹，总氮（TN）损失为8.3 kg Mg⁻¹。这些分别相当于初始DM的30.1%、初始TC的52.8%和初始TN的41.6%。对于WBM，DM损失为268 kg Mg⁻¹，TC损失为154 kg Mg⁻¹，TN损失为1.40 kg Mg⁻¹，分别相当于初始量的26.5%、34.5%和11.8%。大部分碳以二氧化碳形式损失，甲烷占比<6%。然而，甲烷对温室气体排放的净贡献更大，因为它捕获热量的效率是二氧化碳的21倍。氧化亚氮（N₂O）排放对于SBM为0.077 kg N Mg⁻¹，对于WBM为0.084 kg N Mg⁻¹，占总氮损失的1%至6%。以二氧化碳 - 碳当量计的总温室气体排放，SBM（368.4 ± 18.5 kg Mg⁻¹）和WBM（349.2 ± 24.3 kg Mg⁻¹）之间没有显著差异。然而，368.4 kg C Mg⁻¹（二氧化碳 - 碳当量）的排放量大于SBM的初始TC含量（330.5 kg Mg⁻¹），这引发了堆肥对碳固存净效益的问题。需要进一步研究以评估堆肥对整体温室气体排放和碳固存的影响，并充分研究牲畜粪便管理方案。
