长期不同化肥氮用量对设施菜地土壤氮素矿化和硝化作用的影响  

Effects of Long-term Different Chemical Nitrogen Rates on Soil Nitrogen Mineralization and Nitrification in Greenhouse Vegetable Field

作　　者：武星魁 施卫明[1] 徐永辉 闵炬[1] WU Xingkui;SHI Weiming;XU Yonghui;MIN Ju(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Yixing City Construction Culture Tourism Group Co.,Ltd.,Yixing,Jiangsu 214200,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049 [3]宜兴市城建文旅集团有限公司,江苏宜兴214200

出　　处：《土壤》2021年第6期1160-1166,共7页Soils

基　　金：国家自然科学基金项目(31872185);江苏省农业科技自主创新资金项目(CX(18)1005)资助。

摘　　要：为揭示长期施用不同化肥氮对设施菜地土壤供氮能力的影响,选取连续种植15年不同化肥氮用量下的设施菜地土壤,采用好气密闭培养法研究长期不同化肥氮用量对设施菜地土壤氮素矿化和硝化作用的影响。供试土壤为5个氮施用水平,分别为:不施化肥氮(CK),常规化肥氮(100%N),常规化肥氮上减氮20%(80%N)、40%(60%N)、60%(40%N)。结果表明:与初始矿质氮量相比,培养结束后CK、40%N、60%N、80%N和100%N处理土壤矿质氮变化量分别为38.9、44.7、20.6、–32.7、–87.6 mg/kg;CK、40%N和60%N处理土壤矿质氮变化量分别占各自土壤全氮量的2.7%、2.5%和1.0%,80%N和100%N处理土壤矿质氮量与初始矿质氮量相比下降1.3%和3.1%;CK、40%、60%N、80%N和100%N处理土壤硝化速率分别为19.3、11.2、4.9、5.2、1.2 mg/(kg·d)。长期高量化肥氮(80%N和100%N)投入下,设施菜地土壤氮素矿化和硝化速率显著降低,土壤供氮能力下降,土壤pH降低可能是导致土壤矿化和硝化作用受到抑制的原因之一。鉴于此,设施蔬菜种植体系在现有施氮水平上应减少化肥氮投入,科学优化施肥,维持土壤的供氮能力,确保设施土壤的可持续利用。In order to reveal the effects of long-term application of different chemical nitrogen(N)fertilizers on soil N supply capacity in greenhouse vegetable fields,soil samples were selected from a 15-year vegetable experiment field,and then the effects of long-term N fertilizer dosage on soil N mineralization and nitrification were studied by aerobiotic soil incubation method,in which five N application rates were designed as:no chemical N fertilization(CK),conventional chemical N rate(100%N),and the conventional chemical N rate reduction of 20%(80%N),40%(60%N)and 60%(40%N),respectively.The results showed that compared with the initial,the mineralized N of CK,40%,60%,80%and 100%N treatments after incubation were 38.9,44.7,20.6,–32.7 and–87.6 mg/kg,respectively.The mineralized N of CK,40%N and 60%N treatments accounted for 2.7%,2.5%and 1.0%of the total soil N content,respectively.The mineralized N of 80%N and 100%N treatments decreased by 1.3%and 3.1%compared with the initial.The nitrification rates under CK,40%,60%,80%and 100%N treatments were 19.3,11.2,4.9,5.2 and 1.2 mg/(kg soil·d),respectively.Long-term high rate of chemical N input(80%N and 100%N)significantly reduced soil N mineralization and nitrification rates and decreased soil N supply capacity in greenhouse vegetable field.The reduction of soil pH may be one of the reasons for the inhibition of soil mineralization and nitrification.In view of this,the greenhouse vegetable production system should reduce the amount of chemical N rate,and promote scientific and optimal fertilization in order to guarantee the sustainable utilization of vegetable soils.

关 键 词：长期施肥 氮转化 pH 矿化作用 硝化作用 

分 类 号：S19[农业科学—农业基础科学]