{"title":"Conversion of arable land to perennial bioenergy crops increases soil organic carbon stocks on the long term","authors":"Fabien Ferchaud , Sylvain Marsac , Bruno Mary","doi":"10.1016/j.agee.2025.109637","DOIUrl":null,"url":null,"abstract":"<div><div>Perennial C4 bioenergy crops can combine high productivity and low input requirements. However, their impact on soil organic carbon (SOC) stocks remains uncertain. The aim of this study was to assess the long-term impact of converting arable land to perennial bioenergy crops on SOC stocks for two crop species (miscanthus and switchgrass) and several crop management practices (nitrogen fertilization, harvest date and irrigation). We analyzed two long-term experiments located in northern and southern France. Both sites were sampled initially and after 12 or 13 years. SOC stocks were calculated at equivalent soil mass in each site and δ<sup>13</sup>C measurements were used to calculate changes in “new” and “old” SOC stocks. SOC stocks in the old ploughed layer increased significantly in both sites but most of the SOC storage occurred in the topsoil layer (∼0–5 cm). SOC storage rate was fairly similar between miscanthus and switchgrass but was much greater in the southern site than in the northern site (0.96 <em>vs</em> 0.26 t C ha<sup>−1</sup> yr<sup>−1</sup>). This larger storage rate was mainly explained by higher carbon inputs, as suggested by the higher accumulation rate of new SOC (1.41 <em>vs</em> 0.86 t C ha<sup>−1</sup> yr<sup>−1</sup>). No significant effect of the management practices on the SOC change rate could be detected, but early harvest systematically reduced SOC storage compared to late harvest (by 33 % for miscanthus and 12 % for switchgrass). Higher carbon inputs due to late harvest or irrigated conditions were partly compensated by a higher old SOC decrease.</div></div>","PeriodicalId":7512,"journal":{"name":"Agriculture, Ecosystems & Environment","volume":"388 ","pages":"Article 109637"},"PeriodicalIF":6.0000,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Agriculture, Ecosystems & Environment","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167880925001690","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Perennial C4 bioenergy crops can combine high productivity and low input requirements. However, their impact on soil organic carbon (SOC) stocks remains uncertain. The aim of this study was to assess the long-term impact of converting arable land to perennial bioenergy crops on SOC stocks for two crop species (miscanthus and switchgrass) and several crop management practices (nitrogen fertilization, harvest date and irrigation). We analyzed two long-term experiments located in northern and southern France. Both sites were sampled initially and after 12 or 13 years. SOC stocks were calculated at equivalent soil mass in each site and δ13C measurements were used to calculate changes in “new” and “old” SOC stocks. SOC stocks in the old ploughed layer increased significantly in both sites but most of the SOC storage occurred in the topsoil layer (∼0–5 cm). SOC storage rate was fairly similar between miscanthus and switchgrass but was much greater in the southern site than in the northern site (0.96 vs 0.26 t C ha−1 yr−1). This larger storage rate was mainly explained by higher carbon inputs, as suggested by the higher accumulation rate of new SOC (1.41 vs 0.86 t C ha−1 yr−1). No significant effect of the management practices on the SOC change rate could be detected, but early harvest systematically reduced SOC storage compared to late harvest (by 33 % for miscanthus and 12 % for switchgrass). Higher carbon inputs due to late harvest or irrigated conditions were partly compensated by a higher old SOC decrease.
期刊介绍:
Agriculture, Ecosystems and Environment publishes scientific articles dealing with the interface between agroecosystems and the natural environment, specifically how agriculture influences the environment and how changes in that environment impact agroecosystems. Preference is given to papers from experimental and observational research at the field, system or landscape level, from studies that enhance our understanding of processes using data-based biophysical modelling, and papers that bridge scientific disciplines and integrate knowledge. All papers should be placed in an international or wide comparative context.