Soil Type of The World

SOIL TYPES OF THE WORLD 

Soil is an essential part of growing own food. There are four main soil types: clay, loam, sand, and peat, with loam being a mixture of sand and clay.  Clay soil  structure is  sticky when wet, and hard as a brick when dry.  In Sandy soil the nutrients are quickly washed away. Also sandy soil suffers in drought conditions as it drains so much faster than a heavy soil. Loam is the intermediate between clay soil and sandy soil. It drains well, but also holds nutrients well. With the addition of a little humus, and sometimes a little lime, a loam is often the best soil for most growing. Peat soil is very rare which is a pity because it contains so many nutrients. Peat forms when vegetable matter dies and settles at the bottom of a swamp. Climate, vegetation and soil are intimately related and soil formation is affected by vegetation and climate.

In the world Dokucharyev gave first classification of soil.  

He divided the soil into 3 groups which are :

(i)         Zonal Soil :

            ZONE                                                             SOIL TYPE

            1.         Boreal                                                Tundra (dark brown soil)

            2.         Taiga                                                  Light grey podsol soil

            3.         Forest steppe                                    Grey and dark grey soil

            4.         Desert steppe                                   Chestnut brown or white soil

            5.         Steppe                                               Chernozem soil

            6.         Desert                                                Aerial yellow soil

            7.         Sub tropical and tropical forest      Laterite and red soil

(ii)        Transitional Soil

            1.         Dry land moor soil

            2.         Carbonate containing soil

            3.         Secondary alkaline soil

(iii)       Abnormal Soil

            1.         Moor soil        -           Cold region soil

            2.         Alluvial soil    -           Transported through water

            3.         Aeolian soil   -           Tranported through wind

The most recent classification of soil type is proposed by soil survey staff of USDA (1960), which is following:

            1.         Entisols          -           Azonal soil

            2.         Vertisol           -           Grumu soil

            3.         Inceptisol       -           Brown forest soil

            4.         Aridisol           -          Desert redish desert soil

            5.         Mollisol          -          Chernozem, chestnut, brunizem

            6.         Spodosol       -            Podsol, brown podsolic soil

            7.         Uttisol             -          Red yellow podsolic, laterite soil

            8.         Oxysol            -          Laterite soil, latosols

            9.         Histosol          -          Bog soil

            10.       Alfisol             -         Grey brown podsol soil