首页|Laboratory and numerical modelling of irrigation infiltration and nitrogen leaching in homogeneous soils

Laboratory and numerical modelling of irrigation infiltration and nitrogen leaching in homogeneous soils

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Nitrogen(N)plays a key role in crop growth and production;however,data are lacking especially regarding the interaction of biochar,grass cover,and irrigation on N leaching in saturated soil profiles.Eighteen soil columns with 20-cm diameter and 60-cm height were designed to characterize the effects of different grass cover and biochar combinations,i.e.,bare soil+0%biochar(control,CK),perennial ryegrass+0%biochar(C1),Festuca arundinacea+0%biochar(C2),perennial ryegrass+1%biochar(C3),perennial ryegrass+2%biochar(C4),perennial ryegrass+3%biochar(C5),F.arundinacea+1%biochar(C6),F.arundinacea+2%biochar(C7),and F.arundinacea+3%biochar(C8),on periodic irrigation infiltration and N leaching in homogeneous loess soils from July to December 2020.Leachates in CK were 10.2%-35.3%higher than those in C1 and C2.Both perennial ryegrass and F.arundinacea decreased the volumes of leachates and delayed the leaching process in the 1%,2%,and 3%biochar treatments,and the vertical leaching rate decreased with biochar addition.The N leaching losses were concentrated in the first few leaching tests,and both total N(TN)and nitrate(NO3-)-N concentrations in CK and C1-C8 decreased with increasing leaching test times.Biochar addition(1%,2%,and 3%)could further reduce the leaching risk of NO3--N and the NO3--N loss decreased with biochar addition.However,compared to 1%biochar,2%biochar promoted the leaching of TN under both grass cover types.The N leaching losses in CK,C1,C2,C3,C4,C6,and C7 were primarily in the form of NO3--N.Among these treatments,CK,C1,and C2 had the highest cumulative leaching fractions NO3--N(>90%),followed by those in C3,C4,C6,and C7(>80%).The cumulative leaching fraction of NO3--N decreased with increasing leaching test times and biochar addition,and 3%biochar addition(i.e.,C5 and C8)reduced it to approximately 50%.The one-dimensional advective-dispersive-reactive transport equation can be used as an effective numerical approach to simulate and predict NO3--N leaching in saturated homogeneous soils.Understanding the effects of different biochar and grass combinations on N leaching can help us design environmentally friendly interventions to manage irrigated farming ecosystems and reduce N leaching into groundwater.

leaching lossnitrate nitrogenbiochargrass coveranalytical modelling

Lei WU、Ruizhi LI、Yan WANG、Zongjun GUO、Jiaheng LI、Hang YANG、Xiaoyi MA

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Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A & F University,Yangling 712100(China)

Blackland Research and Extension Center,Texas A&M AgriLife Research,Texas A&M University,Temple TX 76502(USA)

State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A & F University,Yangling 712100(China)

College of Water Resources and Architectural Engineering,Northwest A & F University,Yangling 712100(China)

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国家自然科学基金国家自然科学基金国家自然科学基金National Fund for Studying Abroad,China

520701584227707351679206201706305014

2024

土壤圈(英文版)
中国土壤学会,中科院南京土壤研究所和土壤与农业可持续发展国家重点实验室

土壤圈(英文版)

CSTPCD
影响因子:0.477
ISSN:1002-0160
年,卷(期):2024.34(1)
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