2025-03-28 中国科学院（CAS）
中国科学院昆明植物研究所の研究チームは、半乾燥地域における連作障害の解決策として、ジャガイモと飼料作物の輪作システムを検討しました。連作は土壌有機炭素（31.9 g/kgから15.7 g/kg）と全窒素含有量（3.7 g/kgから1.6 g/kg）を減少させ、土壌肥沃度の深刻な低下を示しました。一方、ジャガイモと飼料作物の輪作は、土壌の物理的・化学的性質を大幅に改善しました。
土壌中の主要な細菌門であるプロテオバクテリアとアクチノバクテリアの相対的存在量が高まり、土壌健康の維持に寄与しました。しかし、連作は特定の抗生物質耐性遺伝子（ARGs）の増加を引き起こし、土壌微生物群集内での耐性形質の選択を促進することが示唆されました。飼料作物（オーツ麦やオーツ麦-エンドウ混作）の成長段階によってARGsへの影響が異なり、植物の成長と根からの分泌物が微生物群集とARGsの増殖に影響を与えることが示されました。
この研究は、作物の多様化、特に飼料作物の導入が土壌肥沃度と生態系の安定性を高める持続可能な農業戦略として有効であることを示しています。
＜関連情報＞
- https://english.cas.cn/newsroom/research_news/life/202503/t20250328_908878.shtml
- https://www.sciencedirect.com/science/article/pii/S2666916125000283?via%3Dihub
ジャガイモ栽培における環境影響と微生物汚染リスクへの対策：半乾燥地域における飼料栽培の利点 Combatting environmental impacts and microbiological pollution risks in Potato cropping: benefits of forage cultivation in a semi-arid region
Xudong Sun, Yousif Abdelrahman Yousif Abdellah, Guangyan Wang, Huasen Wang, Jishao Jiang, Yu Zhang, Caspar C.C. Chater, Yongping Yang, Yuanwen Duan, Fuqiang Yu, Dong Liu
Resources, Environment and Sustainability Available online: 18 March 2025
DOI:https://doi.org/10.1016/j.resenv.2025.100216
Graphical abstract
Highlights
- Continuous potato cropping decreases soil fertility with reduced SOC and TN.
- Oat cultivation enhances mineral nitrogen availability and soil properties.
- Forage cultivation alters the structure of soil archaeal communities.
- 20 abundant antibiotic-resistance genes significantly vary across cultivations.
Abstract
Continuous potato cropping in semi-arid regions, which are vulnerable to erosion, reduces tuber yields and leads to a decline in soil quality. This research delves into the impact of forage cultivation on soil bacterial and archaeal communities and the associated hazard-related virulence genes and antibiotic resistance genes (ARGs) within potato cropping systems. The study reveals that distinct crop rotation schemes significantly alter soil physicochemical properties. Compared to non-potato cultivation, continuous potato cropping substantially reduces soil organic carbon from 31.9 g kg <?XML:NAMESPACE PREFIX = “[default] http://www.w3.org/1998/Math/MathML” NS = “http://www.w3.org/1998/Math/MathML” />−1 to 15.7 g kg −1 and total nitrogen from 3.7 g kg −1 to 1.6 g kg −1, indicating a notable deterioration in soil fertility. Among the ten identified phyla, Proteobacteria demonstrates the highest relative abundance, from 34.6% to 38.4%, closely followed by Actinobacteria, ranging from 20.5% to 36.0%. These two phyla likely play a crucial role in maintaining soil health. Moreover, continuous potato cultivation (CPC) results in more specific ARGs than non-potato cultivation (NPC). This phenomenon implies that CPC may select for particular resistance traits within the soil microbiome, potentially due to changes in the composition of the soil microbiota. Forage crops (oats or a mixture of oats and peas) exhibit varying effects on ARGs at different growth stages. The differences observed between the flowing and maturity stages of oats suggest that plant growth and the composition of root exudates can influence microbial communities and the prevalence of ARGs. The Mantel test further indicates that specific soil properties impact the abundance of certain microbial taxa and determine the expression of key functional genes, including those associated with antibiotic resistance. These findings underscore the intricate interactions among microbial communities, genes, and soil health, providing essential guidance for formulating agricultural practices to manage soil health and mitigating problems such as antibiotic resistance in continuously cropped soils.
Importantly, this study highlights the significant benefits of crop diversification, primarily through the incorporation of forage crops, in safeguarding soil health and maintaining microbial diversity within potato cropping systems. The results offer valuable perspectives for developing sustainable agricultural strategies, which can enhance soil fertility and promote ecosystem stability in semi-arid regions.
