老芒麦与苜蓿间作草地牧草-土壤化学计量特征  

Effects of Elymus sibiricus and Medicago sativa intercropping on pasture soil C,N,and P stoichiometric characteristics

作　　者：独双双 李霞 路欣 贾燕伟 赛宁刚 祁希明 沈李瑜 张秀山 祁娟[1] DU Shuangshuang;LI Xia;LU Xin;JIA Yanwei;SAI Ninggang;QI Ximing;SHEN Liyu;ZHANG Xiushan;QI Juan(College of Pratacultural Science,Gansu Agricultural University/Key Laboratory of Grassland Ecosystem,Ministry of Education/Gansu Grassland Engineering Laboratory/China-US Center for Grazing Land Ecosystem Sustainability,Lanzhou 730070,Gansu,China)

机构地区：[1]甘肃农业大学草业学院/草业生态系统教育部重点实验室/甘肃省草业工程实验室/中-美草地畜牧业可持续研究中心,甘肃兰州730070

出　　处：《草业科学》2024年第11期2664-2674,共11页Pratacultural Science

基　　金：国家牧草产业技术体系项目(CARS-34);国家自然科学基金项目(31660684)。

摘　　要：以不同间作比例(2꞉4、2꞉5、2꞉6、2꞉7和2꞉8)建植第3年的紫花苜蓿(Medicago sativa)与老芒麦(Elymus sibiricus)草地为试验对象,通过研究牧草-土壤碳(C)、氮(N)、磷(P)含量及化学计量特征,探讨间作模式下各组分C、N、P转化与利用特性,揭示最佳的间作比例及其生长限制因素。结果表明,间作下老芒麦相对紫花苜蓿的C、N和P竞争比率均小于1,紫花苜蓿具有较强的养分竞争能力。紫花苜蓿有机C含量较其单播差异显著,且2꞉4间作处理显著提高17.35%(P<0.05),而老芒麦仅在2꞉7和2꞉8间作处理下较单播显著提高5.39%和1.62%(P<0.05);2꞉7间作处理下,紫花苜蓿与老芒麦N含量均较高,分别较其单播显著提高20.08%和6.83%(P<0.05),紫花苜蓿C꞉N较其单播显著降低12.32%(P<0.05),N꞉P显著提高18.48%(P<0.05),老芒麦N꞉P和C꞉P较其单播显著提高27.63%和25.86%(P<0.05),而老芒麦C꞉N在2꞉4间作处理下较其单播显著降低18.56%(P<0.05)。土壤全氮、全磷含量及N꞉P未表现出显著差异,土壤有机碳和C꞉N在2꞉6间作处理下较紫花苜蓿单播分别显著提高了33.12%和116.26%(P<0.05)。冗余分析表明,牧草与土壤均受N素限制,2꞉7间作处理更有助于缓解N素限制。In this study,Medicago sativa(alfalfa)and Elymus sibiricus grasslands in the third year of different intercropping ratios(2꞉4,2꞉5,2꞉6,2꞉7,and 2꞉8)were used as experimental subjects.The carbon(C),nitrogen(N),and phosphorus(P)contents and stoichiometric characteristics in forage soil were studied to explore the conversion and utilization characteristics of each component in the five intercropping treatments to reveal the optimal intercropping ratio and its growth limiting factors.We found that the competition ratios of C,N,and P of E.sibiricus to alfalfa were less than one in intercropping treatments,i.e.,alfalfa had a stronger nutrient competition ability than E.sibiricus.The C content of alfalfa was significantly different from that of the E.sibiricus monoculture,and that of the 2꞉4 intercropping treatment increased significantly by 17.35%(P<0.05),whereas the C content of E.sibiricus under the 2꞉7 and 2꞉8 intercropping treatments increased significantly by 5.39%and 1.62%(P<0.05)compared with the E.sibiricus monoculture,respectively.Under the 2꞉7 intercropping treatment,the N content of alfalfa and E.sibiricus were higher,increasing significantly by 20.08%and 6.83%compared with that of the E.sibiricus monoculture(P<0.05).Furthermore,the alfalfa C꞉N decreased significantly by 12.32%(P<0.05),N꞉P increased significantly by 18.48%,and the N꞉P and C꞉P of E.sibiricus increased significantly by 27.63%and 25.86%compared with the ratio of the E.sibiricus monoculture(P<0.05),respectively.The C꞉N under the 2꞉4 intercropping treatment decreased significantly by 18.56%(P<0.05)compared to that of the monoculture.Soil total N content,total P content,and N꞉P were not significantly different between treatments,whereas soil organic C and C꞉N increased significantly by 33.12%and 116.26%compared to the alfalfa monoculture under the 2꞉6 intercropping treatment(P<0.05).Redundancy analysis showed that both forage and soil were limited by N and 2꞉7 intercropping treatment was more effective to allevi

关 键 词：老芒麦 紫花苜蓿 间作比例 植物养分 营养竞争比率 土壤养分 化学计量比 

分 类 号：S812.4[农业科学—草业科学]