Spatial distributions of total nitrogen(TN) in soils are difficult to estimate because of their inherent spatial variabilities and lack of sufficient sample data.Soil-landscape model,based on parent material and topographic factors,was generated through applying GIS spatial analysis technique and a digital elevation model (DEM) in large areas.Based on 151 sample data, spatial distribution characteristic of TN was studied.Correlations between TN and topographic factors were analyzed and a regression model was established to predict TN content through linear regression analysis.The results for surface soils (0~20cm) showed that the average content of TN was 1.06g/kg in topsoil,with TN content between 0.5g/kg and 1.0 g/kg occupying the largest area (1580km2,49.3% of the total area) and that over 2.0g/kg the smallest(127km2,3.9% of the total area)in spatial distribution. Also,soils derived from sandstone and shale had the lowest average TN content (0.88 g/kg soil),soils developed on phyllite showed the highest average TN content (1.35 g/kg soil).Aspect among topographic variables had an important effect on TN content.The correlations of TN content with parent rocks,elevation and aspect were positively significant (P<0.05),slope exposure had the highest correlation with TN content (r=0.62).The correlation of TN content with slope was insignificant (r=-0.03).In the soils of the whole study area,the step regression analysis of the TN content, topographic factors and parent rocks showed that elevation,slope exposure and parent rocks were the best factors for predicting the TN content in topsoil (P<0.05).The multiple linear regression model is: TN=0.095+0.005×parent rocks+0.001×elevation+0.115×slope exposure classification n=113 R2= 0.637 The spatial distribution of TN content could be predicted by using a multiple linear regression model and DEM ( with a 30m×30m grid).
CHENG Xian-fu, SHI Xue-zheng, YU Dong-sheng, WANG Hong-jie
. Spatial estimation of soil total nitrogen using GIS: a case study in Xingguo county, Jiangxi Province[J]. GEOGRAPHICAL RESEARCH, 2007
, 26(1)
: 110
-116
.
DOI: 10.11821/yj2007010014
[1] 白军红,邓伟,张玉霞.莫莫格湿地土壤氮磷空间分布规律研究.水土保持学报,2001,15(4):79~81.
[2] Spain A V.Influence of environmental conditions and some soil chemical properties on the carbon and nitrogen contents of some tropical Australian rainforest soils.Aust. J.Soil Res. ,1990,28:825~839.
[3] 王淑平,周广胜,吕育财,等.中国东北样带(NECT)土壤碳、氮、磷的梯度分布及其与气候因子的关系.植物生态学报, 2002,26(5):513~517.
[4] Neil J M,Philip J R.Spatial predicition of soil properties using environmental correlation.Geoderma, 1999,89:67~94.
[5] 程先富,史学正,于东升,等.丘陵山区林地土壤养分状况研究.水土保持学报,2003,17(2):28~30.
[6] 程先富,史学正,于东升,等.亚热带典型地区土壤全氮和地形、母岩的关系研究.水土保持学报,2004,18(2):137~139.
[7] Schmidt M G, Schreier H,Shsh P B. Factors affecting the nutrient status of forest sites in a mountain watershed in Nepal. J. Soil Sci. ,1993,44:417~425.
[8] Cain M L,Suber S, Evans J P,et al.Sampling spatial and temporal variation in soil nitrogen availability.Oecologia,1999,118:397~404.
[9] Raghubanshi A S.Effect of topography on selected soil properties and nitrogen mineralization in a dry tropical forest.Soil Biol. Biochem. ,1992,24:145~150.
[10] Datta D K,Gupta S K, Nath S,et al.Variations in the characteristics and nutrient status of soils of the eastern Himalayas as influenced by elevation. Int. J. Tropical Agricult. , 1989,7:208~215.
[11] Robertson G P,Huston M A,Evans F C,et al. Spatial variability in a successional plant community: patterns of nitrogen availability. Ecology,1988,69:1517~1524.
[12] Ryel R J,Caldwell,M M, Manwaring J H.Temporal dynamics of soil spatial heterogeneity in sagebrush-wheatgrass steppe during a growing season.Plant Soil,1996,184:299~309.
[13] 刘付程,史学正,于东升,等.太湖流域典型地区土壤全氮的空间变异特征.地理研究,2004,23(1):63~70.
[14] 陈伏生,曾德慧,陈广生.土地利用变化对沙地土壤全氮空间分布格局的影响.应用生态学报,2004,15(6):953~957.
[15] Cheng X F, Shi X ZH,Yu D SH,et al.Using GIS spatial distribution to predict soil organic carbon in subtropical China.Pedosphere,2004,14(4):425~430.
[16] 程先富,史学正,于东升,等.兴国县森林土壤有机碳库及其与环境因子的关系.地理研究,2004,23(2):211~217.
[17] 刘光崧.土壤理化分析与剖面描述.北京:中国标准出版社,1996.5~6.
[18] SPSS.SPSS for Windows-Based System, User’s Guide Release 6.0. Marja J. Norusis/SPSS Inc.1993.
[19] Bourgeon,King H D,Coutueier.A comparison of Kriging with external drift and simple linear regression for predicting soil horizon thickness with different sample densities.Geoderma,2000,97:255~271.
[20] Odeh I O A,McBratney A B,Chittleborough D J.Spatial predition of soil properties from landform attributes derived from a digital elevation model.Geoderma,1994,63:197~214.
[21] Chaplot V,Walter C,Curmi P.Improving soil hydromorphy prediction according to DEM resolution and available peological data.Geoderma, 2000, 97:405~422.
