摘要
设施菜地因大水大肥管理方式导致的氮素淋失已成为当前关注焦点。探寻氮素淋失阻控技术需要首先探明土壤中NO3--N的运移和淋失过程,找到淋失阻控的关键点,从而实现蔬菜栽培高产量低环境成本。本研究以京郊设施菜地黄瓜-番茄轮作系统为研究对象,通过田间试验获取土壤温度、湿度、NO3--N含量等数据,对反硝化-分解(DNDC)模型进行参数校验,并以农民常规种植模式为基线情景,设置改变土壤基础性质、灌溉量、施氮量等不同情景,运用DNDC模型对设施菜地系统土壤氮素运移及淋溶损失进行定量评价。结果表明:经验证后的DNDC模型能够较好地模拟蔬菜产量、5 cm土壤温度和0~20 cm土壤孔隙含水率变化以及NO3--N的迁移过程,是模拟和评价氮素运移和损失的有效工具。模拟不同情景表明,设施菜地0~60 cm土壤NO3--N累积主要受灌溉水量和氮肥施入量的影响,此外土壤pH和土壤有机碳的变化也是影响NO3--N运移的重要因子。节水节肥是设施菜地氮素淋失减量的最有效方法,相比常规措施,同时减少20%灌溉量和20%施氮量可明显降低59.04%的NO3--N淋失量。同时,在节水节肥的基础上改变灌溉方式并提高20%土壤有机碳含量,在保证蔬菜产量的前提下,能够进一步降低69.04%的NO3--N淋失量。可见,DNDC模型为设施菜地NO3--N淋失评价和阻控提供了一个较好的解决方案。在当前重点关注减氮节水等管理措施的同时,提高土壤本身的质量,不失为一种更有效的减少设施菜地氮素淋失的途径。
Nitrogen(N)leaching is caused by the mismanagement of water and fertilizer in greenhouse vegetable fields.Understanding N movement and leaching process is important for achieving high crop yields at low environmental costs.A field experiment was conducted for a greenhouse cucumber-tomato rotation system in the suburbs of Beijing,China.The DeNitrification-DeComposition(DNDC)model was used to quantitatively evaluate the soil N transport and leaching loss in the facility vegetable field after considering factors obtained from field experiments,such as soil temperature,humidity,and nitrate nitrogen(NO3--N)content.Conventional practices were selected as the baseline scenario,and the modeled scenarios,such as changes in soil properties,irrigation,and N application,were set according to the baseline.The results showed that the DNDC model can better simulate the vegetable yield,5 cm soil temperature,0–20 cm soil water-filled pore space,and NO3--N migration process,indicating that it is an effective tool for simulating and evaluating N transport and leaching in vegetable field soil.The modeling scenarios showed that the accumulation of NO3--N in the 0–60 cm soil was primarily affected by the irrigation amount and N application;soil pH and organic carbon were also important factors affecting NO3--N migration.Increasing irrigation amount significantly accelerated the downward movement of NO3--N,and increasing N application promoted the accumulation of NO3--N at the surface and a depth of 20 cm.Increasing soil pH lessened NO3--N surface accumulation;and to a certain extent,increasing soil organic carbon delayed the downward movement of NO3--N.Controlling water and fertilizer was the most effective method for mitigating N leaching.Compared with conventional measures,reducing irrigation and N application simultaneously by 20%significantly reduced NO3--N leaching by 59.04%.Changing irrigation method and increasing soil organic carbon content by 20%(to save water and fertilizer)further reduced NO3--N leaching by 69.04%.The DNDC model is a useful method for evaluating and controlling NO3--N leaching in vegetable fields.Changing management practices,such as N and water amounts as the soil quality improves,may be an effective way to reduce N leaching in vegetable fields.
作者
雷豪杰
李贵春
丁武汉
徐驰
王洪媛
李虎
LEI Haojie;LI Guichun;DING Wuhan;XU Chi;WANG Hongyuan;LI Hu(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)
出处
《中国生态农业学报（中英文）》
CAS
CSCD
北大核心
2021年第1期38-52,共15页
Chinese Journal of Eco-Agriculture
基金
国家重点研发计划项目(2018YFD0800402,2016YFD0800101)
国家自然科学基金项目(41671303)资助。
关键词
设施菜地
氮淋失
水氮控制
土壤有机碳
DNDC模型
Facility vegetable field
Nitrogen leaching
Water and nitrogen control
Soil organic carbon
DNDC model
