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草业学报 ›› 2025, Vol. 34 ›› Issue (10): 51-61.DOI: 10.11686/cyxb2024469

• 研究论文 • 上一篇    下一篇

紫花苜蓿与库尔勒香梨间作体系氮素转移途径的定量分析

明艳1,2(), 窦梓镱1,2(), 郑伟1,2(), 王宁欣1,2, 陈雪1,2   

  1. 1.新疆农业大学草业学院,新疆 乌鲁木齐 830052
    2.新疆维吾尔自治区草地资源与生态重点实验室,新疆 乌鲁木齐 830052
  • 收稿日期:2024-11-25 修回日期:2025-01-16 出版日期:2025-10-20 发布日期:2025-07-11
  • 通讯作者: 郑伟
  • 作者简介:E-mail: zw065@126.com
    明艳(1998-),女,新疆焉耆人,在读硕士。E-mail:1975917961@qq.com
    窦梓镱(1998-),女,新疆昌吉人,在读博士。E-mail:3517669621@qq.com.第一联系人:共同第一作者These authors contributed equally to this work.
  • 基金资助:
    国家自然科学基金项目(32060402);新疆维吾尔自治区高校科研计划重点项目(XJEDU2019I013)

Quantitative analysis of nitrogen transfer pathways in intercropping systems between alfalfa and Korla pear

Yan MING1,2(), Zi-yi DOU1,2(), Wei ZHENG1,2(), Ning-xin WANG1,2, Xue CHEN1,2   

  1. 1.College of Grassland Science,Xinjiang Agricultural University,Urumqi 830052,China
    2.Key Laboratory of Grassland Resources and Ecology in Xinjiang Uygur Autonomous Region,Urumqi 830052,China
  • Received:2024-11-25 Revised:2025-01-16 Online:2025-10-20 Published:2025-07-11
  • Contact: Wei ZHENG

摘要:

在库尔勒香梨行间种植豆科牧草增加库尔勒香梨氮素供应已被大家所证实,但豆科牧草与库尔勒香梨间作下氮素利用与转移的具体途径还不清晰。本研究以紫花苜蓿与库尔勒香梨间作为对象,设置紫花苜蓿与库尔勒香梨根系间完全隔离(PS)、仅无机氮离子转移(NS)、有菌丝通道(J)和完全不隔离(S)4种氮素转移途径,利用15N同位素示踪法定量测定紫花苜蓿与库尔勒香梨间作体系的生物固氮能力、氮素转移能力及二者影响因素,量化分析氮素转移途径及其贡献。结果表明:1)与单作紫花苜蓿相比,间作紫花苜蓿的固氮量为4.74 g·m-2,提升了0.18 g·m-2。2)与完全隔离(PS)途径相比,完全不隔离(S)和无机氮离子转移(NS)途径固氮量分别增加了33.6%、5.4%,有菌丝通道(J)途径则下降了71.7%,转氮量分别增加了224.8%、119.8%和4.7%;4种途径下的转氮效率呈S(0.92%)>NS(0.63%)>J(0.30%)>PS(0.28%)的规律。3)固氮酶活性极显著影响豆科牧草固氮量(P<0.01),土壤菌丝密度则显著影响固氮率(P<0.05);AM真菌侵染强度和频度显著影响转氮率和转氮量(P<0.05)。因此,紫花苜蓿与梨树间作下的氮素转移途径主要为无机氮离子和AM真菌菌丝共同存在下的完全不隔离途径,库尔勒香梨从与紫花苜蓿间作中共收益了33.61%的氮素。这为林草间作体系的氮素高效利用,节约土地资源,解决肥料短缺等方面提供了新的有效方法。

关键词: 林草间作, 氮素利用效率, 氮转移途径, AM真菌菌丝途径, 无机离子途径

Abstract:

The husbandry methodology of increasing nitrogen supply to Korla pear (Pyrus sinkiangensis) by planting legume forage between rows of Korla pear has been well established, but the specific pathways of nitrogen utilization and transfer under such intercropping are not clear. This study, focused on alfalfa (Medicago sativa) and Korla fragrant pear intercropping. Four nitrogen transfer pathways were established: complete root isolation (PS), inorganic nitrogen ion transfer only (NS), hyphal channel transfer (J), and no isolation (S). The 15N isotope tracing method was used to quantify the biological nitrogen fixation capacity, nitrogen transfer effciency, and influencing factors in the intercropping system, as well as to analyze the contributions of each pathway. The results showed: 1) The nitrogen fixation of intercropped alfalfa was 4.74 g·m-2, which was 0.18 g·m-2, greater than mono-cropped alfalfa. 2) Compared with PS, the amount of nitrogen fixation increased under S increased by 33.6%, increased under NS by 5.4% and decreased under J by 71.7%, while the amount of nitrogen transfer increased by 224.8%, 119.8% and 4.7%, respectively. The nitrogen transfer efficiencies under the four pathways ranked S (0.92%)>NS (0.63%)>J (0.30%)>PS (0.28%). 3) Nitrogen fixing enzyme activity had a highly significant effect on the amount of nitrogen fixation by the leguminous intercrop (P<0.01), while soil hyphal density significantly positively effect on the nitrogen fixation rate (P<0.05) and the intensity and frequency of AM fungal infestation was significantly positively correlated with the rate and amount of nitrogen transfer (P<0.05). Therefore, the nitrogen transfer pathway under intercropping of alfalfa and pear was mainly a dual pathway of inorganic nitrogen ions and AM fungal mycelium, and Korla pear gained a total of 33.61% of its total nitrogen from intercropping with alfalfa. This study offers a novel approach to enhancing nitrogen use efficiency, conserving land resources, and addressing fertilizer shortages in tree-forage tercropping system.

Key words: forest-grass intercropping, nitrogen use efficiency, nitrogen transfer pathway, AM fungal mycelium pathway, inorganic ion pathway