河西走廊绿洲区灌溉和施氮肥下苜蓿生殖期叶片养分特性及其与种子产量的关联  

Leaf nutritional traits of alfalfa at the reproductive stage and their correlations with seed yield under different irrigation and nitrogen fertilization levels in the oasis area of the Hexi Corridor

作　　者：本转林 金慧兴 吴晓娟 牟乐 张娇娇 韩云华[1] 杨惠敏[1] BEN Zhuan-lin;JIN Hui-xing;WU Xiao-juan;MU Le;ZHANG Jiao-jiao;HAN Yun-hua;YANG Hui-min(College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China)

机构地区：[1]兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业学报》2025年第1期94-106,共13页Acta Prataculturae Sinica

基　　金：国家重点研发计划课题(2022YFD1300801);国家牧草产业技术体系-青藏高原牧草栽培岗位科学家(CARS-34)资助。

摘　　要：灌溉和施肥是提高苜蓿种子生产力的重要管理措施,进一步阐明其影响种子产量形成的机制有助于水肥管理措施优化。苜蓿生殖期叶片养分特性与种子产量的关系尚不明确。研究不同灌溉[全生育期充分灌溉(W1)、轻度亏水(W2)和中度亏水(W3),以及现蕾期和结荚期亏灌(W4)、返青期和结荚期亏灌(W5)、返青期和现蕾期亏灌(W6)]和施氮肥(10和40 kg·hm^(-2),分别以N1和N2表示)下,苜蓿生殖生长期叶片养分含量、重吸收效率及其与种子产量的关系。结果表明:1)随灌溉量减少和生育时期推进,生殖期绿叶N、P含量降低;亏缺灌溉下绿叶养分含量不低于W3甚至W2;现蕾期和结荚期N2下绿叶养分含量显著高于N1。生殖期枯叶N、P含量随灌溉量减少和生育时期推进呈升高趋势;亏缺灌溉下现蕾期枯叶N含量低于W1~W3,而结荚期和成熟期高于W1甚至W2;成熟期N2下枯叶N含量高于N1,而结荚期N2下P含量较高。2)随灌溉量减少和生育时期推进,生殖期叶片养分重吸收效率降低;亏缺灌溉下现蕾期养分重吸收效率高于W1~W3,结荚期和成熟期不低于W3;现蕾期N2下N重吸收效率高于N1,其他时期相反,而各时期N2下P重吸收效率较高。3)W3下种子产量低于W1和W2,特定时期亏缺灌溉下种子产量不低于W1甚至W2,W6下最高;N2下种子产量显著高于N1。4)种子产量与结荚期绿叶N、P含量、养分重吸收效率极显著正相关,与枯叶养分含量显著负相关。因此,灌溉和施氮肥对苜蓿生殖期叶片养分含量有显著影响,并表现出生育时期特异性。结荚期养分重吸收能增强种子形成所需养分的供应能力。综合来看,全生育期轻度亏水或返青期和现蕾期亏灌而结荚期充分灌溉下施氮肥40kg·hm^(-2)时可获得较高苜蓿种子产量。Irrigation and fertilization are important measures to improve alfalfa seed productivity.Understanding the mechanisms of seed yield formation will be helpful for optimizing water and fertilizer management.The relationships between leaf nutrient characteristics at the reproductive growth stage and the seed yield of alfalfa remain unclear.We investigated leaf nutrient contents and nutrient resorption efficiencies in alfalfa plants at the reproductive stage,and their relationships with seed yield,under different irrigation and nitrogen(N)fertilization conditions.Six irrigation treatments were set up comprising differing rates of irrigation at re-greening in spring,budding and podding growth stages.The irrigation treatments were:full irrigation(450,150 mm at each irrigation,W1);mild water deficit(360,120 mm at each irrigation,W2)and moderate water deficit(270,90 mm at each irrigation,W3);300 mm irrigation allocated 150,75 and 75 mm,respectively,at re-greening,budding and podding stages(W4);300 mm irrigation allocated 75,150 and 75 mm,respectively,at re-greening,budding and podding stages(W5);and 300 mm irrigation allocated 75,75 and 150 mm,respectively,at re-greening,budding and podding stages(W6).The N fertilization treatments were 10 kg·ha^(-1)(N1)or 40 kg·ha^(-1)(N2)applied at re-greening.N and P contents of green and senescent leaves were measured at budding,podding stages and at crop maturity to allow calculation of N and P resorption.It was found that:1)With decreasing irrigation and advancing growth stages,there were decreases in the N and phosphorus(P)contents in green leaves at the reproductive growth stage.The nutrient contents of green leaves were not lower in W4 and W5 than in W3 or even W2.The nutrient contents in green leaves at the budding and podding stages were significantly higher in N2 than in N1.The N and P contents in senesced leaves at the reproductive growth stage increased as irrigation decreased and growth stages advanced.The N content of senesced leaves at the budding stage was lower in W4

关 键 词：河西走廊 苜蓿 调亏灌溉 种子生产 养分重吸收 

分 类 号：S541[农业科学—作物学]