不同施氮處理對西藏綠肥植物幼苗根系生長的影響

摘要 為了解青藏高原地區施用氮肥對綠肥植物根系產生的效應。以綠肥植物（紫花苜蓿和箭筈豌豆）為試驗材料，采取不同施氮水平（0、0.06、0.12、0.18、0.24、0.30 g/dm2）在西藏農牧學院設計盆栽試驗，研究不同施氮處理對綠肥植物根系、生長特征的影響。結果表明，紫花苜蓿根系長度、投影面積、面積、表面積、體積、分叉數等指標在不同施氮水平下都呈先下降后上升再下降后上升的趨勢，且在N5處理（0.30 g/dm2）時變化幅度最大，高于對照組。箭筈豌豆根尖數等指標都表現出先降低后增加再降低的趨勢；根長、根投影面積、根面積、根表面積、根體積和根分叉數呈先逐漸增加后降低再增加的趨勢。當超過0.18 g/dm2（N3處理）時，會顯著影響箭筈豌豆的根系生長。對于紫花苜蓿，低氮水平對根系生長影響不明顯，高濃度的氮元素有助于促進植物的根系生長。對于箭筈豌豆，氮肥施用過量會顯著影響箭筈豌豆的根系生長。因此，在綠肥植物的生長管理中要控制好適宜氮素濃度，以達到最佳的生產效益。研究結果為西藏地區氮肥施用技術的完善提供了理論依據，也為紫花苜蓿和箭筈豌豆的大面積栽培提供了科學的參考。

關鍵詞 施氮；紫花苜蓿；箭筈豌豆；根系生長

中圖分類號 Q 945 文獻標識碼 A

文章編號 0517-6611（2024）22-0151-06

doi：10.3969/j.issn.0517-6611.2024.22.032

開放科學（資源服務）標識碼（OSID）：

Effects of Different Nitrogen Application Treatments on Root Growth of Green Manure Plants Seedlings in Xizang

ZHAO Shuai， DAI Xue， BAI Yao-qiang et al

（Xizang Agriculture and Animal Husbandry University， Nyingchi，Xizang 860000）

Abstract To study the effect of nitrogen fertilizer on the root system of green fertilizer plants in Qinghai-Tibet Plateau，green manure plants （alfalfa and Vicia sativa） were used as experimental materials in pot experiments with different nitrogen application levels （0，0.06，0.12，0.18，0.24，0.30 g/dm2） in Xizang University of Agriculture and Animal Husbandry.The effects of different nitrogen application treatments on root characteristics of green manure plants were studied. The results showed as follows：the root length，projected area，area，surface area，volume and branch number of alfalfa showed a trend of first decreasing，then increasing and then decreasing under different nitrogen application levels，and the changes were the largest under N5 treatment （0.30 g/dm2），which were higher than those in the control group. The number of root tips of Vicia sativa decreased first，then increased and then decreased.Root length，root projection area，root area，root surface area，root volume and root branching number showed a trend of first gradually increasing，then decreasing and then increasing.Root growth of Vicia sativa was significantly affected when common vetch was more than 0.18 g/dm2（N3 treatment）. In general，for alfalfa，the effect of low nitrogen level on root growth was not obvious，and high concentration of nitrogen was helpful to promote the growth of plant roots.Root growth of Vicia sativa was significantly affected by overapplication of nitrogen fertilizer. Therefore，the appropriate nitrogen concentration should be controlled in the growth management of green manure plants to achieve the best production benefits.The results provide a theoretical basis for the improvement of nitrogen fertilizer application technology in Tibet，and also provide a scientific reference for the large-scale cultivation of alfalfa and Vicia sativa.

Key words Nitrogen application;Alfalfa;Vicia sativa;Root system growth

西藏處于高海拔地區，環境條件相對惡劣，是我國的生態高地。根據最新西藏土壤調查^［1］，耕地質量大部分偏低，需要采取多種措施做好培肥提高肥力工作。在國家生態高地、國家減肥增效、高產高效等背景下，通過綠肥植物的種植是提高肥力、又不破壞環境的常見措施。……