溶解性有机碳溶液灌溉和苜蓿间作消减黄土区苹果园深层土壤硝酸盐的研究  

Study on the Reduction of Nitrate in Deep Soil of Apple Orchard in Loess Area by Irrigation of Dissolved Organic Carbon Solution and Intercropping of Alfalfa

作　　者：代洪伟 丁艳宏 高晓东 李昌见[1,3] 任敏 宋小林 赵西宁 DAI Hongwei;DING Yanhong;GAO Xiaodong;LI Changjian;REN Min;SONG Xiaolin;ZHAO Xining(Ministry of Education Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Northwest A&F University,Yangling,Shanxi 712100,China;College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling,Shanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shanxi 712100,China;College of Horticulture,Northwest A&F University,Yangling,Shanxi 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西杨凌712100 [2]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [3]中国科学院水利部水土保持研究所,陕西杨凌712100 [4]西北农林科技大学园艺学院,陕西杨凌712100

出　　处：《土壤学报》2025年第1期201-213,共13页Acta Pedologica Sinica

基　　金：国家重点研发计划项目(2021YFD1900700);国家自然科学基金项目(42125705)资助。

摘　　要：近年来,黄土区苹果园由于氮肥使用不当,导致土壤中硝酸盐的大量累积,将严重威胁土壤生态安全。溶解性有机碳(Dissolved organic carbon,DOC)输入和深根系豆科作物间作是消减苹果园深层土壤硝酸盐的潜在可行途径,但其效果与影响因素研究目前较薄弱。为此,本研究在渭北黄土区苹果园中设置了灌溉DOC溶液(D)、苜蓿间作(M)、灌溉DOC溶液+苜蓿间作(D+M)以及对照(CK)四个处理,测定0~600 cm土层硝酸盐、DOC、土壤有机碳(Soil organic carbon,SOC)、含水率及反硝化微生物丰度等指标。研究表明:D和D+M处理下,0~400 cm土壤剖面硝酸盐消减比例达到50%左右,但单一的M处理消减效果不明显;D处理消耗的DOC与硝酸盐之间的C、N质量消耗比例约为5︰1,D+M处理的C、N质量消耗比例约为4.35︰1;D和D+M处理均增加了0~600 cm土层nirS、nirK和nosZ反硝化基因拷贝数,并提高了DOC、SOC和反硝化微生物对硝酸盐消减的贡献率。总体而言,D+M处理消减硝酸盐效果最好,可作为黄土区果园深层土壤硝酸盐治理的可行措施。【Objective】In recent years,due to improper use of nitrogen fertilizer,a large accumulation of nitrate in the soil has seriously threatened the soil ecological security of the apple orchard in the loess area.The input of dissolved organic carbon(Dissolved organic carbon,DOC)and intercropping with deep-rooted leguminous crops may be a potentially feasible way to reduce nitrate in the deep soil of the apple orchard,However,research on the feasibility of this approach its effectiveness and influencing factors is currently weak.【Method】Therefore,this study set up four treatments in the apple orchard in the northern loess area of Wei River:DOC solution irrigation(D),alfalfa intercropping(M),DOC solution irrigation+alfalfa intercropping(D+M),and control(CK).Various indicators such as nitrate nitrogen,DOC,soil organic carbon(Soil organic carbon,SOC),moisture content,and denitrifying microbial abundance in the 0–600 cm soil layers were measured.【Result】The study found that under the D and D+M treatments,the reduction rate of nitrate nitrogen in the 0–400 cm soil profile reached around 50%,but the effect of the single M treatment was not significant.The carbon-to-nitrogen consumption ratio between consumed DOC and nitrate was about 5︰1 in the D treatment,and about 4.35︰1 in the D+M treatment.Both the D and D+M treatments increased the copy numbers of nirS,nirK,and nosZ denitrification genes in the 0–600 cm soil layers,and enhanced the contribution of DOC,SOC,and denitrifying microbes to nitrate reduction.【Conclusion】Overall,the D+M treatment showed the best nitrate reduction effect and can be considered a feasible measure for controlling deep soil nitrate in orchards in the loess area.

关 键 词：黄土高原 溶解性有机碳 硝态氮 反硝化功能基因 苜蓿 

分 类 号：S661.1[农业科学—果树学] S153.6[农业科学—园艺学]