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Clay, loess & loam - what is good soil ? Yana Wang 17.01.2007
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2 Soil
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3 Soil Science Society of America (SSSA) Soil is the unconsolidated mineral material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants.
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4 composition of soil by volume Ideal fertile soil Mineral 45% Organic matter 5% Water 25% Air 25% http://jpkc.snnu.edu.cn/geog/webasp/kj/kejian/6%20turangquan.ppt
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5 soil particle Rock and mineral weathering Parent material Soil formation Soil particle physical chemical biological Primary particle Secondary particle
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7 classification systems of soil Criterion: equivalent diameter or effective diameter of soil particle Soil texture: gravel >2 mm sand 0.05~2 mm silt 0.002~0.05 mm clay < 0.002 mm
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8 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt
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9 soil particle Size mm Minerals (%) SiO 2 Al 2 O 3 Fe 2 O 3 CaOMgOK2OK2ONa 2 OP2O5P2O5 1~0.283.929.341.121.790.381.781.210.08 0.2~0.0473.8713.474.213.051.051.731.530.12 0.04~0.0170.1514.045.862.151.051.483.890.21 0.01~0.00267.2118.917.851.451.632.511.270.29 <0.00244.0827.6721.810.581.611.100.960.36 The larger the particles are, the more SiO 2 the soil has, the more barren it is. http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt
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10 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt
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11 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt
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12 Soil typesSoil texture clay loess silt, with small amount of clay and sand loamsand, silt, clay
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13 Clay Mineral: Al 2 [(OH) 4 Si 2 O 5 ] · nH 2 O Al 2 O 3 · 2SiO 2 · 2H 2 O etc. poor aeration and drainage plastic when wet, when dry become firm
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15 Clay is only good for paddy rice field.
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16 loess Mineral: most carbonates small amount of clay minerals good aeration, water-holding ability easy to be transported by river and wind for example: 1935 dust storm in midwest United States
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19 loam mixture of clay, silt and sand sandy, plastic when wet easily water contain more nutrients than sandy soils ideal fertile soil
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20 other parameters organic matter pH value etc.
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21 organic matter microorganism soil animal organic manure http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/3.1.ppt
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22 organic matter element: 90~95% C 、 O 、 H 、 N 、 P 、 K 、 Ca 、 Mg 、 Fe 、 Si 、 Zn 、 Cu 、 B 、 Mo 、 Mn etc. soil fertility: soil fertility low low- medium medium high- medium high OM ( % ) <0.50.5~1.01.0~1.21.2~1.5>1.5
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23 soil pH value climate: high temperature and humidity accelerates the weathering microorganism: for example: breath from bacterium environment: acid rain
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24 The best pH value for plants is 6,5. in soilpHin soilpH Na 2 CO 3 NaHCO 3 MgCO 3 CaCO 3 CaCO 3 -withCO 2 Ca(HCO 3 ) 2 12~13 8.5~9.5 11.47 10.20 8.48 6.13~8.4 CaSO 4 H 2 O Na 2 SO 4 , MgSO 4 , NaCl , MgCl 2 NH 4 Cl H 2 CO 3 KAl(SO 4 ) 2 ; AlCl 3 7.0 7.7~7.1 6.3~6.5~6.8 4.7 3.9~5.7 2~4 soil pH value http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt
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25 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt
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26 Fruit PLANT TYPESOIL pH Apple5.0-6.5 Apricot6.0-7.0 Arbor Vitae6.0-7.5 Blueberry, high bush4.0-5.0 Cherry, sour6.0-7.0 Cherry, sweet6.0-7.5 Crab apple6.0-7.5 Cranberry, large4.2-5.0 Peach6.0-7.5 Pineapple5.0-6.0 Raspberry, red5.5-7.0 Strawberry5.0-6.5 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt
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27 Vegetables PLANT TYPESOIL pH Asparagus6.0-8.0 Beets, table6.0-7.5 Broccoli6.0-7.0 Cabbage6.0-7.5 Carrot5.5-7.0 Cauliflower5.5-7.5 Celery5.8-7.0 Cucumber5.5-7.0 Lettuce6.0-7.0 Muskmelon6.0-7.0 Onion5.8-7.0 Potato4.8-6.5 Rhubarb5.5-7.0 Spinach6.0-7.5 Tomato5.5-7.5 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt
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28 Summary Clay: perfect water-holding ability good for paddy rice field Both loess and loam can be tillable soil for most of plants. But loam is better, because of more nutrient. more than 1.5% organic matter pH value by 6.5
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29 Reference 1. C.Y.Huang, Soil Science,1991 2. J. Bachmann, G. Arye, M. Deurer, S. K. Woche, R. Horton,Y. Chen, J. Plant Nutr. Soil Sci. 2006, 169, 745–753 3. http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/html/link.html 4. http://soil.gsfc.nasa.gov/soilform/deposits.htm 5. http://nhjy.hzau.edu.cn/kech/2006/turangxue/dzja.html 6. http://en.wikipedia.org/wiki/Clay 7. http://en.wikipedia.org/wiki/Loess 8. http://en.wikipedia.org/wiki/Loam
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30 Thank you for your attention!
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