氮磷施肥对退化禾草混播草地生产力和土壤理化性质的影响  

Effects of nitrogen and phosphorus fertilization on grassland productivity and soil physicochemical properties of degraded grass⁃mixed grasslands

作　　者：孟愉欣 刘婉婷 王正文 王俊杰 陈新栋 王世林 曹文侠[1] MENG Yuxin;LIU Wanting;WANG Zhengwen;WANG Junjie;CHEN Xindong;WANG Shilin;CAO Wenxia(College of Pratacultural Science,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Sino-U.S.Centers for Grazingland Ecosystem Sustainability,Lanzhou 730070,China;Wuqi County Fruit Industry Technology Development Service Center,Yan′an 717600,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,中-美草地畜牧业可持续发展研究中心,兰州730070 [2]吴起县果业技术发展服务中心,延安717600

出　　处：《生态学报》2025年第7期3204-3217,共14页Acta Ecologica Sinica

基　　金：国家牧草产业技术体系(CARS-34)。

摘　　要：施肥是恢复和提升退化草地生产力的重要措施,但单次施肥在时间尺度上对高寒草地植被和土壤质量的影响仍不明确。旨在探究祁连山高寒区建植20年以上的多年生退化禾草混播草地在单次氮磷施肥后对植被和土壤理化性质的持续影响。采用随机区组试验设计,设置四个氮肥水平(N_(0):0 kg N/hm^(2)、N_(1):50 kg N/hm^(2)、N_(2):100 kg N/hm^(2)、N_(3):200 kg N/hm^(2))和四个磷肥水平(P_(0):0 kg P_(2)O_(5)/hm^(2)、P_(1):65 kg P_(2)O_(5)/hm^(2)、P_(2):117 kg P_(2)O_(5)/hm^(2)、P_(3):210 kg P_(2)O_(5)/hm^(2)),氮磷配施组合共16种处理。评估了施肥当年(2021年)和第三年(2023年)的草地生产力和土壤理化特性。结果显示,2021年,高氮水平(N_(3))显著提高地上生物量(AGB),并增加了土壤有机质(SOM)、速效氮(AN)和速效磷(AP)含量;2023年,高磷水平(P_(2)和P_(3))的AGB显著高于其他处理,并显著提升了AN、AP和全磷(TP)含量。氮肥、磷肥分别于AGB、SOM、AN显著相关;磷肥还与AP和TP显著相关;氮磷交互显著影响SOM和全氮(TN)含量;年际分别与AGB、SOM、AN显著相关。2021年,氮肥和磷肥对所有指标均有促进作用;2023年磷肥对AGB、SOM和TN仍有显著促进作用,而氮肥效果不显著,表明磷肥的遗留效应大于氮肥。结构方程模型显示,氮肥对2021年AGB有直接影响,磷肥显著影响2023年AGB,并通过AP等间接提高地下生物量(BGB)。综上,施肥当年氮肥占主导作用,高氮中磷(200 kg N/hm^(2)和117 kg P_(2)O_(5)/hm^(2))模式效果最佳;施肥第三年磷肥的肥效仍在发挥作用,低氮高磷(50 kg N/hm^(2)与117和210 kg P_(2)O_(5)/hm^(2))配施的持续效果更好。综合生态与经济效益,单次高磷与低氮配施可发挥施肥的增产作用和更稳定持续的遗留效应。本研究结果可为高寒地区退化禾草混播草地培育复壮实践提供重要参考。Fertilization is crucial for restoring and enhancing the productivity of degraded grasslands;however,the enduring impacts of a one⁃time fertilizer application on the vegetation and soil quality in alpine grasslands are not well understood.This study sought to assess the long⁃term effects of a one⁃time application of nitrogen and phosphorus fertilizers on the vegetation and soil physicochemical properties in alpine perennial grass⁃mixed grasslands that have been established for over two decades.The experiment used a randomized block design with four levels each of nitrogen(N_(0):0,N_(1):50,N_(2):100,N_(3):200 kg N/hm^(2))and phosphorus fertilizers(P_(0):0,P_(1):65,P_(2):117,P_(3):210 kg P_(2)O_(5)/hm^(2)),along with their combinations,yielding a total of 16 treatment combinations.Grassland productivity and soil physicochemical properties were assessed in the first and third year after fertilization(2021 and 2023,respectively).The findings indicated that the elevated nitrogen level(N_(3))notably enhanced aboveground biomass(AGB),as well as soil organic matter(SOM),available nitrogen(AN),and available phosphorus(AP)levels in 2021.The AGB was still significantly higher than the other treatments at medium and high phosphorus levels(P_(2) and P_(3)),as well as AN,AP,and soil total phosphorus(TP)contents in 2023.There was a significant correlation between nitrogen and phosphorus fertilizers and AGB,SOM,and AN,respectively;phosphorus fertilizer showed a significant association with AP and total phosphorus(TP);nitrogen⁃phosphorus interactions substantially impacted SOM and total nitrogen(TN)levels,and inter⁃annual correlations were significantly linked to AGB,SOM,and AN,respectively.Nitrogen and phosphorus fertilizers promoted all measured indicators in 2021,while phosphorus fertilizers still significantly enhanced AGB,SOM,and TN in 2023,indicating that the legacy effect of phosphorus fertilizers was greater than that of nitrogen fertilizers.The structural equation model revealed that nitrogen fertilizer effec

关 键 词：氮磷施肥 混播草地 草地生产力 土壤理化性质 施肥遗留效应 

分 类 号：S812.2[农业科学—草业科学]