磷添加对青海扁茎早熟禾各器官生物量及生态化学计量特征的影响  

Effects of Phosphorus Addition on Biomass and Ecological Stoichiometric Characteristics of Organs in Poa pratensis var.anceps Gaud cv.Qinghai

作　　者：王佳豪 何克燕 鲍根生[1] 徐航 何霖 魏小星[1] WANG Jiahao;HE Keyan;BAO Gensheng;XU Hang;HE Lin;WEI Xiaoxing(The Academy of Animal and Veterinary Science,Qinghai University/Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Xining,810016,China)

机构地区：[1]青海大学畜牧兽医科学院/青海省青藏高原优良牧草种质资源利用重点实验室,青海西宁810016

出　　处：《中国草地学报》2024年第1期37-46,共10页Chinese Journal of Grassland

基　　金：青海省创新平台(2021-ZJ-T01);西部之光计划(2021-XBZG-12);青海省“高端创新人才计划”(2020-PYBJ-84);国家自然科学基金(31760711);青海省林草新技术推广项目(QSCZ-2022-001)。

摘　　要：磷对植物体内氮代谢和氮效率均有促进作用,添加适量的磷肥有助于提高牧草产量和抗逆性。为探究不同磷添加下牧草不同器官生物量及元素浓度的变化规律,本研究设置7个磷添加梯度(0、30、60、90、120、150、180 kg/hm^(2)),分析了5龄青海扁茎早熟禾各器官(根、茎、叶)生物量的分配、生态化学计量特征及二者的相互关系。结果表明:(1)施磷量的增加能够显著影响青海扁茎早熟禾生物量,呈先增加后降低变化趋势:其中90 kg/hm^(2)施磷水平下地上和地下生物量最高,分别比对照增加73.99%、7.31%;(2)随施磷量增加,青海扁茎早熟禾各器官碳、氮、磷含量呈先增加后降低的变化趋势:其中150 kg/hm^(2)施磷水平下,根系氮和磷含量最高,较对照组增加37.05%和34.63%,而90 kg/hm^(2)水平下,叶片氮和磷含量最高,分别比对照增加11.60%和37.66%;(3)不同器官碳、氮、磷含量存在较大差异:其中,叶片碳、氮含量高于根系,而根系磷含量却高于叶片;(4)各器官生物量与碳、氮、磷含量呈显著正相关性(P<0.05),地上植株生物量(叶片、茎秆)与碳氮比、碳磷比呈极显著负相关性(P<0.01)。由此可见,磷添加能显著调控青海扁茎早熟禾营养元素吸收和平衡能力,适度磷添加(90 kg/hm^(2))对高效利用高龄青海扁茎早熟禾具有重要的生态和生产意义。Supplementing forage crops with an appropriate amount of phosphorus(P)effectively enhances nitrogen metabolism and utilization,leading to improved forage yield and stress resilience.This study investigated the effects of P addition on the biomass distribution,tissue ecological stoichiometric characteristics,and their interactions in different organs(roots,stems,and leaves)of a 5-year-old Poa pratensis var.anceps Gaud cv.Qinghai.Seven P addition gradients were applied:0,30,60,90,120,150,180 kg/hm^(2).The results showed as follows:(1)Plant biomass initially increased withing increasing P addition,peaking at 90 kg/hm^(2)with a 73.99%rise in aboveground biomass and a 7.31%rise in belowground biomass compared to the control.This trend gradually reversed at higher P levels;(2)Similarly,carbon(C),nitrogen(N),and P contents in different organs peaked at specific P addition levels before declining.Notably,root N and P reached their highest values(37.05%and 34.63%increases,respectively)at 150 kg/hm^(2),while leaf N and P peaked at 90 kg/hm^(2)(11.60%and 37.66%higher than the control,respectively).(3)Interestingly,leaf C and N content consistently exceeded those in roots,while root P content was higher than in leaves;(4)Importantly,all organ biomasses displayed significant positive correlations with C,N and P contents(P<0.05).Notably,aboveground biomass(leaves and stems)exhibited a highly significant negative correlation with C∶N and C∶P(P<0.01).These observations suggest that P addition significantly regulates nutrient uptake and balance in Poa pratensis var.anceps Gaud cv.Qinghai.Furthermore,our findings indicate that moderate P addition(90 kg/hm^(2))offers a crucial balance between maximizing biomass production and achieving efficient utilization in mature stands of this forage grass.

关 键 词：磷添加 青海扁茎早熟禾 生态化学计量特征 生物量 

分 类 号：S543.9[农业科学—作物学]