酸化对水稻-土壤系统氮分配和N_(2)O排放的影响  

Effects of acidification on nitrogen allocation in rice-soil system and N_(2)O emission

作　　者：张宗祥 李华玮 尚文鼎 曹传莉 孙梦雨 李笑笑 董召荣[1] 宋贺[1] ZHANG Zongxiang;LI Huawei;SHANG Wending;CAO Chuanli;SUN Mengyu;LI Xiaoxiao;DONG Zhaorong;SONG He(Anhui Key Laboratory of Farmland Ecological Conservation and Pollution Prevention and Control/College of Agriculture,Anhui Agricultural University,Hefei 230036,China)

机构地区：[1]农田生态保育与污染防控安徽省重点实验室/安徽农业大学农学院,合肥230036

出　　处：《农业环境科学学报》2024年第2期452-461,共10页Journal of Agro-Environment Science

基　　金：安徽省高等学校科学研究项目(2022AH050876);安徽农业大学人才科研资助项目(rc312104);农田生态保育与污染防控安徽省重点实验室开放基金项目(FECPP202202);沿淮气候智慧型稻麦系统丰产栽培技术研发项目(FYHT20230036)。

摘　　要：为研究土壤酸化对水稻-土壤系统氮转化、分配和氮损失的影响,以水稻-土壤系统为研究对象,设置中性(pH 7,CK)、弱酸(pH 6,T1)、中强酸(pH 5,T2)和强酸(pH 4,T3)4个土壤递增酸度处理,比较了不同酸度下水稻产量、氮素积累量、氮代谢酶活性、氮素利用效率、氮平衡和N_(2)O排放等指标的差异。结果表明,随着土壤酸度增加,水稻植株氮素积累、利用效率和产量呈现先增加后降低的趋势。相关性分析表明,拔节期氮素积累量与叶片中硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)和谷氨酸脱氢酶(GDH)以及茎秆中GS和GOGAT活性呈显著正相关;开花期氮素积累量与穗中的NR、GS、GOGAT和GDH活性呈显著正相关。T1、T2和T3处理N_(2)O累积排放量与CK处理相比分别降低20.3%、58.0%和76.7%;单位产量下的N_(2)O排放量呈现递减的趋势。氮平衡分析表明,相比于CK处理,T2和T3处理氮素表观损失分别降低15.8%和21.1%,水稻氮吸收量分别降低1.5%和15.3%,土壤无机氮残留量分别增加41.2%和88.2%,氮素盈余率分别提高2.2个和7.1个百分点。土壤酸化至中强酸和强酸时,会分别通过抑制水稻拔节期茎叶和开花期穗部的氮代谢过程降低氮素积累量、利用效率和产量。土壤酸化会降低稻田N_(2)O累积排放量,同时也会降低单位产量N_(2)O排放量。此外,中强酸和强酸度土壤还会通过降低水稻氮吸收量和增加播前土壤无机氮量,提高土壤无机氮残留量和氮素盈余率,增加环境风险。Soil acidification is a significant factor constraining rice production in China.Severe soil acidification can lead to imbalance in crop-soil nitrogen(N)transformation,which reduces rice yields and increases environmental risks.However,there is a lack of systematic research related to the impact of soil acidification on N transformation,allocation,and N losses in rice-soil systems.In this study,rice-soil systems with four soil acidity treatments were investigated:neutral(pH 7,CK),weakly acidic(pH 6,T1),moderately acidic(pH 5,T2),and strongly acidic(pH 4,T3).Differences in rice yield,N accumulation,N metabolic enzyme activities,N use efficiency,N balance,and nitrous oxide(N_(2)O)emissions were compared.With increasing soil acidity,N accumulation,utilization efficiency,and yield of rice plants displayed trends of increase followed by decrease.Correlation analysis indicated that N accumulation at the jointing stage was significantly positively correlated with the activities of nitrate reductase(NR),glutamine synthetase(GS),glutamate synthetase(GOGAT),and glutamate dehydrogenase(GDH)in leaves,as well as GS and GOGAT activities in stems.Similarly,N accumulation at the flowering stage was significantly positively correlated with NR,GS,GOGAT,and GDH activities in panicles compared to the CK treatment.N_(2)O cumulative emissions in the T1,T2,and T3 treatment groups were reduced by 20.3%,58.0%,and 76.7%,respectively.The N_(2)O emissions per unit yield exhibited a decreasing trend followed by an increase.N balance analysis showed that,compared with CK,the apparent loss of N in the T2 and T3 treatments was reduced by 15.8% and 21.1%,respectively;rice N uptake was reduced by 1.5% and 15.3%,respectively;soil inorganic N residue was increased by 41.2% and 88.2%,and the N surplus rate was increased by 2.2 and 7.1 percentage points,respectively.When soil acidification develops to moderately and strongly acidity levels,it could reduce N accumulation,utilization efficiency,and yield by inhibiting N metabolism processes in the stem

关 键 词：土壤酸化 水稻 氮素利用效率 产量 N_(2)O 土壤氮平衡 

分 类 号：S154.4[农业科学—土壤学] S156.6[农业科学—农业基础科学]