Publication Date:
2019
Description:
〈p〉Straw incorporation is a common long-term practice to improve soil fertility in croplands worldwide. However, straw amendments often increase methane (CH〈sub〉4〈/sub〉) emissions from rice paddies, one of the main sources of anthropogenic CH〈sub〉4〈/sub〉. Intergovernmental Panel on Climate Change (IPCC) methodologies to estimate CH〈sub〉4〈/sub〉 emissions from rice agriculture assume that the effect of straw addition remains constant over time. Here, we show through a series of experiments and meta-analysis that these CH〈sub〉4〈/sub〉 emissions acclimate. Effects of long-term (〉5 years) straw application on CH〈sub〉4〈/sub〉 emissions were, on average, 48% lower than IPCC estimates. Long-term straw incorporation increased soil methanotrophic abundance and rice root size, suggesting an increase in CH〈sub〉4〈/sub〉 oxidation rates through improved O〈sub〉2〈/sub〉 transport into the rhizosphere. Our results suggest that recent model projections may have overestimated CH〈sub〉4〈/sub〉 emissions from rice agriculture and that CH〈sub〉4〈/sub〉 emission estimates can be improved by considering the duration of straw incorporation and other management practices.〈/p〉
Electronic ISSN:
2375-2548
Topics:
Natural Sciences in General
