Dong, Xiaoyu

Fu, Hua

Guo, Ding

Li, Xiaodong

Li, Xudong

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings 21st International Grassland Congress / 8th International Rangeland Congress Change in Soil NH4+‐N and NO3- under Different Land Use Types in the Longzhong Part of Loess Plateau Ding Guo Lanzhou University, China Xiaoyu Dong Lanzhou University, China Xiaodong Li Lanzhou University, China Xudong Li Lanzhou University, China Hua Fu Lanzhou University, China Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/2-2/11 The 21st International Grassland Congress / 8th International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 ]356　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅰ 　Grasslands/Rangelands Resources and Ecology ——— Soil Quality and Plant NutritionChange in soil NH＋4 ‐N and NO－3 ‐N under different land use types in the Longzhong part of LoessplateauDing Guo , X iaoyu Dong , X iaodong L i ,X udong L i , H ua Fu 倡Key L aboratory o f G rassland A gro‐ecosystem , M inistry o f A griculture , College o f Pastoral A griculture Science andTechnology , L anz hou University , L anz hou 730020 , China ;倡 Corresponding author E‐mail : f uhua＠ lz u .edu .cnKey words :NH ＋４ － N , NO －３ － N , different land use types , Loess plateauIntroduction Nitrogen is a limiting element for plant grow th in many ecosystems . Inorganic N ( NH ＋４ ‐N and NO －３ ‐N) , in soil isthe primary N pool available for plants . The availability of these different N forms can change depending on types of land use( Antonio Gallardo et al , ２００５ ) . The purpose of this study was to research the effect of different land use types on soil N .Materials and methods This study was conducted at the Semi‐Arid Climate and Environment Observatory of Lanzhou University(３５°５７′N , １０４°０９′E) . Elevation is １９６６ m , which means annual air temperature is ６ .７ ℃ and means annual precipitation isabout ３８２ mm . Soil type is Sierozem , Four sites [ fenced grassland ( FG ) , grazing grasslands ( GG ) , millet field ( MF) andfallow cropland ( FC) ] , each １ hm２ and adjacent to one another , were selected for the study . Three sample plots (５０ × ５０ m２ )were randomly located within each site . In May ２００７ , ten soil samples at five soil depths ( ０ － ６０cm) were taken in each plotusing soil cores and each five soil samples from same depth were mixed together . The fresh soil sample passed through ２ mmsieve prior to analysis . Data were analyzed using General ANOVA model .Results Soil NH ＋４ ‐N content at the same soil layer did not differ significantly between different study sites . Soil NH ＋４ ‐N contentwithin a site did not differ significantly between soil layers in May and July ( Figure １ ) . The content of NH ＋４ ‐N was significantlyhigher in May compared to that of July ( p ＜ ０ .０５) ( Figure １) Soil NO －３ ‐N content was ranked according to MF ＞ FC ＞ GG ≥FG ( p ＜ ０ .０５) ,There were some differences between May and July . In May , soil NO －３ ‐N content of the four study sites werehighest in ０‐１０ cm soil layer and decreased with soil depth . In July , the trend of soil NO －３ ‐N content of two grassland was sameas that of May along the soil profile . While farmland appeared inflexion in the １０‐２０ cm layer , the trends of them were toreduce then increase . The highest point of MF was in ４０‐６０ cm , and of FC , was in ３０‐４０ cm ( Figure ２ ) .Figure 1 Soil N H ＋4 ‐N content　 　 　 　 　 　 　 　 　Figure 2 Soil NO －3 ‐N contentConclusions In the Loess plateau , because of alkaline soil , soil NH ＋４ ‐N content was not significantly differenent . Soil NO －３ ‐Ncontent was imported for plant grow th . Soil NO －３ ‐N content was different between May and July between farmland plot . SoilNO －３ ‐N content decreased with soil depth in May , while NO －３ ‐N content tended to increase in July . Cultivation destroys soilphysical structure . In July ２００７ , because a great deal of rainfall , soil NO －３ ‐N content was leached to the deeper soil layers .Compared to farmland , grassland has more cover and root biomass which aides in reducing soil N loss .ReferencesAntonio Gallardo , Rocio Parama′ & Felisa Covelo (２００５) . Soil ammonium vs . Nitrate spatial pattern in six plant communities :simulated effect on plant populations . Plant and Soil , ２２７ , ２０７‐２０９ .Acknowledgments This study was sponsored by the China National Key Projects for Basic Scientific Research (２００６CB４００５０１) .soil N H!-N (mg/kg) 0 1 2 3 4 5 6 0 10 E 20 u ....__,, ..c 30 +-' 0.. ~ 40 -6 so (/) 60 70 soil NO; -N (mg/kg) 0 5 10 15 20 25 30 35 0 10 -----20 E E-30 ..c 0..40 Q) ""O - 50 ·o (/) 60 70 --+- FG-5- FG-7__...... GG-5~ GG-7 -¼- F C-5- F C-7---e- MF -5 ---e- MF -7 

Change in Soil NH\u3csub\u3e4\u3c/sub\u3e\u3csup\u3e\u3csup\u3e+\u3c/sup\u3e\u3c/sup\u3e‐N and NO\u3csub\u3e3\u3c/sub\u3e\u3csup\u3e\u3csup\u3e-\u3c/sup\u3e\u3c/sup\u3e under Different Land Use Types in the Longzhong Part of Loess Plateau

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=2523&amp;context=igc

Change in Soil NH\u3csub\u3e4\u3c/sub\u3e\u3csup\u3e\u3csup\u3e+\u3c/sup\u3e\u3c/sup\u3e‐N and NO\u3csub\u3e3\u3c/sub\u3e\u3csup\u3e\u3csup\u3e-\u3c/sup\u3e\u3c/sup\u3e under Different Land Use Types in the Longzhong Part of Loess Plateau

Abstract

Similar works

Full text

Available Versions

University of Kentucky