植物生态学报 ›› 2020, Vol. 44 ›› Issue (7): 752-762.DOI: 10.17521/cjpe.2019.0337

• 研究论文 • 上一篇    下一篇

紫花苜蓿和斜茎黄耆水力提升作用及其对伴生植物的效应

朱林1,2,*(), 王甜甜1,2, 赵学琳1,2, 祁亚淑3, 许兴1,2   

  1. 1宁夏大学西北土地退化与生态恢复国家重点实验室培育基地, 银川 750021
    2宁夏大学西北退化生态系统恢复与重建教育部重点实验室, 银川 750021
    3宁夏中卫市农业技术推广与培训中心, 宁夏中卫 755099
  • 收稿日期:2019-12-03 接受日期:2020-06-17 出版日期:2020-07-20 发布日期:2020-07-03
  • 通讯作者: *朱林: ORCID:0000-0002-1234-5837,E-mail:zhulinscience@126.com
  • 基金资助:
    国家自然科学基金(31160478);国家自然科学基金(31830135);宁夏回族自治区牧草育种专项(2014NYYZ0401);宁夏自然科学基金(NZ17040)

Hydraulic lift of Medicago sativa and Astragalus laxmannii and its effect on their neighborhood plants

ZHU Lin1,2,*(), WANG Tian-Tian1,2, ZHAO Xue-Lin1,2, QI Ya-Shu3, XU Xing1,2   

  1. 1State Key Laboratory Breeding Base of Land Degradation and Ecological Restoration of Northwestern China, Ningxia University, Yinchuan 750021, China
    2Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in North-western China, Ministry of Education, Ningxia University, Yinchuan 750021, China
    3Center for Extension and Training of Agricultural Technique, Zhongwei, Ningxia 755099, China
  • Received:2019-12-03 Accepted:2020-06-17 Online:2020-07-20 Published:2020-07-03
  • Contact: ZHU Lin: ORCID:0000-0002-1234-5837,E-mail:zhulinscience@126.com
  • Supported by:
    National Natural Science Foundation of China(31160478);National Natural Science Foundation of China(31830135);Forage Breeding Program of Ningxia Hui Autonomous Region(2014NYYZ0401);Natural Science Foundation of Ningxia Hui Autonomous Region(NZ17040)

摘要:

为探讨紫花苜蓿(Medicago sativa)及斜茎黄耆(沙打旺, Astragalus laxmannii)与禾本科牧草混播后的水力提升现象, 揭示深、浅根性牧草的种间关系, 为混播草地的建植提供理论依据, 该研究开展了室外“上下盆”分根盆栽试验、采用土壤水分测定及“重水” (D2O, 氘(D)含量>99.9%)标记法估算了苜蓿及斜茎黄耆分别与‘冬牧70’黑麦(Secale cereal ‘Dongmu 70’)不同混播比例(豆科:禾本科分别为3:7、5:5、7:3)条件下水力提升的发生情况及其对伴生牧草生长生理性状的影响。结果表明: ‘冬牧70’黑麦与斜茎黄耆混播后的产量显著高于其与紫花苜蓿混播后的产量, 同一种禾豆牧草混播组合不同混播比例中, 以AC2 (紫花苜蓿:‘冬牧70’黑麦为5:5)和BC3 (斜茎黄耆:‘冬牧70’黑麦为7:3)混播组合的总产量最高。不同单混播组合的单株整个生育期内日均提水量存在显著差异, 两种豆科牧草在混播时日均提水量均高于单播时, 斜茎黄耆单混播时的日均提水量显著高于紫花苜蓿, BC2组合(斜茎黄耆:‘冬牧70’黑麦为5:5)的日均提水量高于其他混播组合。在用标记水处理下盆土壤后, 各组合上下盆土壤水氢稳定同位素比率(δD)值显著升高。不同禾豆牧草组合上盆土壤水δD及禾本科牧草茎秆水δD、整株碳同位素分辨率(Δ13C)和产量数据表明, 在斜茎黄耆与‘冬牧70’黑麦混播比例为3:7、紫花苜蓿与‘冬牧70’黑麦混播比例为5:5时, 禾本科牧草水分状况或产量好于其他混播比例。以上结果表明, 两种深浅根豆科牧草与浅根性禾本科牧草混播种植时发生了水力提升现象, 两种豆科牧草提升的水分可以被伴生的禾本科牧草所吸收利用。

关键词: 禾豆牧草混播, 水力提升, 稳定同位素技术

Abstract:

Aims A variety of plant species can release soil water which is absorbed from wet soil layers to the dry soil layers during the period when transpiration rate is low (hydraulic lift). The purpose of this study is to explore the phenomenon of hydraulic lift for the mixed sowing combinations of two leguminous forages with gramineous forage, uncover the inter-specific relationship between forages with deep and shallow roots and provide theoretical basis for the establishment of mixed grassland.
Methods A split-root pot experiment was conducted outdoors. Two leguminous forages Medicago sativa and Astragalus laxmannii were sowed individually or sowed with a gramineous forage (Secale cereal ‘Dongmu 70’) with proportions of 3:7, 5:5 and 7:3. While the soil water content was measured continuously, deuteroxide (D2O, D% > 99.9%) tracing technique was adopted to test the occurrence of hydraulic lift and to calculate the lift water quantity.
Important findings The yield of S. Cereal ‘Dongmu 70’ in mixed sowing with A. laxmannii was higher than that with M. sativa. The yield of AC2 (Medicago sativa:gramineae being 5:5) and BC3 (A. laxmannii : gramineae being 7:3) was higher than other mixed sowing proportions in the same mixed sowing combination. There was a significant difference in the average daily water lift during the whole growth period among different single sowing or mixed sowing combinations. The lift water amount for a given leguminous forage was higher in mixed sowing combinations than in single sowing combinations. A. laxmannii displayed higher daily water lift quantity regardless of single sowing or mixed sowing. The average daily water lift of BC2 (A. laxmannii : gramineae being 5:5) was significantly higher than other combinations. Hydrogen stable isotope ratio (δD) of soil water in upper and bottom pots significantly increased after treated with deuteroxide tracer. The values of soil water δD in the upper pot, xylem water δD, whole plant carbon isotope discrimination (Δ13C) and yield of Secale cereal ‘Dongmu 70’ have provided the evidence that the water status or yielding performance of S. cereal ‘Dongmu 70’ in the combinations of BC1 (A. laxmannii : gramineae being 3:7) and AC2 was better than other mixed combinations. This study validated the hypothesis that the phenomenon of hydraulic lift occurred when the deep-rooting leguminous and gramineous forages with shallow root were sown together. The water lift by the tested leguminous forages has been absorbed by their neighboring gramineous forage.

Key words: mixed sowing between leguminous forage and gramineous forage, hydraulic lift, stable isotopic technique