长期施氮和刈割对松嫩平原羊草草甸植物磷吸收的影响  

Effects of Long-term Nitrogen Application and Cutting on Plant Phosphorus Uptake of Leymus chinensis Meadow in Songnen Plain

作　　者：傅浩然 胡明欣 李萌[1] 连小晴 刘涵姿 田雨[1] 李强[2,3] FU Hao-ran;HU Ming-xin;LI Meng;LIAN Xiao-qing;LIU Han-zi;TIAN Yu;LI Qiang(College of Forestry and Grassland Science,Jilin Agricultural University/Jilin Provincial Key Laboratory of Forestry and Grassland Genetics and Breeding,Changchun,Jilin Province 130118,China;Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Changchun,Jilin Province 130102,China;Jilin Provincial Key Laboratory of Grassland Farming,Changchun,Jilin Province 130102,China)

机构地区：[1]吉林农业大学林学与草学学院/吉林省林草遗传育种重点实验室,吉林长春130118 [2]中国科学院东北地理与农业生态研究所,吉林长春130102 [3]吉林省草地畜牧重点实验室,吉林长春130102

出　　处：《草地学报》2024年第11期3462-3471,共10页Acta Agrestia Sinica

基　　金：国家自然科学基金区域创新发展联合基金U23A2004资助。

摘　　要：氮增加背景下刈割可能进一步加剧草地磷限制的进程,然而刈割管理如何改变草地植物磷利用特征仍有待深入研究。据此,本研究以松嫩草地为研究对象,通过野外长期定位观测实验,研究了氮增加和刈割交互作用对植物磷吸收及其相关特征的影响。结果表明:氮的增加降低了土壤中速效磷的含量,提高了氮磷比。同时,刈割加剧了速效磷含量的降低和氮磷比的提升。在氮增加下,植物体内磷浓度降低;而刈割则进一步加剧了植物磷浓度的下降。此外,氮增加还改善了根系形态指标,降低了根际中的无机磷含量,刈割对根系形态的适应性调整也表现出上调作用。这表明在长期施氮导致土壤速效磷减少和氮磷比增加下,植物通过降低磷浓度和调整氮磷比,以及改变根系结构和功能来适应磷的相对限制,而刈割则强化了这种适应机制。Mowing may further intensify P limitation under elevated nitrogen availability.However,how mowing management under N enrichment affects P utilization of grassland plants remains unclear.Therefore,this study focused on the Songnen grassland,and then investigated the interactive effects of N application and mowing on plant P uptake and related plant characteristics by long-term field observations.The results indicated that nitrogen addition reduced the P availability and increased the N:P ratio in the soil.Additionally,mowing further promotes the decline of P availability content and increases the soil N:P ratio.Under N enrichment,the P concentration in plants decreased,and mowing exacerbated the decline in plant P concentration.Moreover,N enrichment improved root morphological indices and reduced the inorganic phosphorus concentration in the rhizosphere,with mowing enhancing the adaptive adjustments of root morphology.This study indicated that long-term nitrogen addition reduces soil P availability and increased the N∶P ratio in the soil,and plants can adapt to relative P limitation by lowering their P concentration for adjusting the N∶P ratio,and regulating root structure for intensifying P acquisition.Mowing can further reinforce these adaptive mechanisms.

关 键 词：羊草草甸 氮添加 刈割 磷吸收 

分 类 号：S812[农业科学—草业科学]