磷添加对陇中黄土高原旱作农田土壤呼吸组分特征与碳平衡的影响  

Effects of phosphorus addition on soil respiration component characteristics and carbon balance in dry farmlands of the Loess Plateau,Longzhong,China

作　　者：甘润 齐鹏[1,2,3] 郭高文 王晓娇 蔡立群 海龙[1] 张仁陟 GAN Run;QI Peng;GUO Gaowen;WANG Xiaojiao;CAI Liqun;HAI Long;ZHANG Renzhi(College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China;State Key Laboratory of Aridland Crop Science,Gansu Agricultural University,Lanzhou 730070,China;Gansu Engineering Research Center for Agriculture Water-Saving,Lanzhou 730070,China;College of Management,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学资源与环境学院,兰州730070 [2]甘肃农业大学干旱生境作物学国家重点实验室,兰州730070 [3]甘肃省节水农业工程技术研究中心,兰州730070 [4]甘肃农业大学管理学院,兰州730070

出　　处：《农业环境科学学报》2023年第3期599-611,共13页Journal of Agro-Environment Science

基　　金：甘肃农业大学青年导师扶持基金项目(GAU-QDFC-2021-20);甘肃省高校创新基金项目(2020B-135);甘肃省自然科学基金项目(21JR7RA830)。

摘　　要：磷素的大量输入,将显著影响陆地生态系统的碳平衡和碳固存,为探究陇中黄土高原旱作农田土壤呼吸及其组分动态变化特征与碳平衡对磷添加的响应,采用完全随机区组设计,设不施磷肥(CK)、低磷(P_(1))、中磷(P_(2))、高磷(P_(3))4个施磷水平,测定春小麦生育期各处理土壤呼吸及其组分与环境因子,计算土壤呼吸温度敏感性指数、净生态系统生产力与碳平衡。研究结果表明,磷添加增加了土壤呼吸及其组分的CO_(2)排放量。与CK处理相比,P_(1)、P_(2)处理和P_(3)处理土壤呼吸CO_(2)累计排放量分别显著增加13.85%、24.86%和26.47%(P<0.05);土壤异养呼吸显著提高了9.09%、9.4%和14.52%(P<0.05);土壤自养呼吸分别提高了18.96%、39.98%和38.33%(P<0.05)。土壤呼吸及其组分受到多因素的共同作用,拟合分析结果表明,土壤水分和温度分别可解释土壤呼吸及其组分速率变异的37.0%~49.7%和69.4%~76.8%。逐步回归和方差分解结果表明,土壤呼吸的主要影响因素为0~5 cm土壤碱性磷酸酶和0~10 cm土壤有机碳;异养呼吸的主要影响因素为0~5 cm土壤β-1,4-葡萄糖苷酶、0~5 cm土壤纤维素二糖水解酶和5~10 cm土壤碱性磷酸酶;自养呼吸的主要影响因素为0~5 cm土壤碱性磷酸酶、0~5 cm土壤速效磷、0~5 cm土壤有机碳和5~10 cm土壤纤维素二糖水解酶。CK、P_(1)、P_(2)处理和P_(3)处理的净生态系统生产力均为正值,其数值分别为2640.10、3412.91、3579.83 kg·hm^(-2)和3790.74 kg·hm^(-2),均表现为土壤碳的“汇”。因此,在陇中黄土高原旱作农田生态系统管理中,应合理地增施磷肥(建议施用115 kg·hm^(-2)),提高土壤固碳效率,科学合理地构建环境保护与经济高效并重的现代化农业生产管理体系。The balance and sequestration of carbon in terrestrial ecosystems can be significantly affected by a large input of phosphorus.Here,we investigated dynamic changes in soil respiration and its components and the response of carbon balance to phosphorus addition in the dry farming areas of central Gansu Province.A completely randomized block design was used Dingxi city,with four levels of phosphorus application:no phosphorus(CK),low phosphorus(P_(1)),medium phosphorus(P_(2)),and high phosphorus(P_(3)).Soil respiration,its components,and other environmental factors were measured in each treatment during the spring wheat growth period.The soil respiration temperature sensitivity index,net ecosystem productivity,and carbon balance were calculated.The results of the study showed that phosphorus addition increased the amount of CO_(2)emitted by soil respiration and its components.Compared with CK,the cumulative CO_(2)emissions of soil respiration increased significantly in the P_(1),P_(2),and P_(3) treatments by 13.85%,24.86%and 26.47%,respectively(P<0.05).Soil heterotrophic respiration increased significantly by 9.09%,9.4%,and 14.52%(P<0.05),while autotrophic respiration increased by 18.96%,39.98%,and 38.33%,respectively(P<0.05).Soil respiration and its components were affected by multiple factors,with fitting analysis showing that soil moisture and temperature accounted for 37.0%–49.7%and 69.4%–76.8%of the variation,respectively.Stepwise regression and variance decomposition showed that the main influences on soil respiration were alkaline phosphatase content in the 0–5 cm soil and 0–10 cm soil organic carbon layers.The main factors influencing soil heterotrophic respiration were 0–5 cm soilβ-1,4-glucosidase,0–5 cm soil cellulose disaccharide hydrolase and 5–10 cm soil alkaline phosphatase.The main factors influencing soil autotrophic respiration were 0–5 cm soil alkaline phosphatase,0–5 cm available phosphorus and 5–10 cm soil cellulose disaccharide hydrolase.All treatments showed a positive net

关 键 词：磷添加 土壤呼吸 碳平衡 土壤酶 黄土高原 

分 类 号：S154.1[农业科学—土壤学]