Soil Characteristics of Some Main Soil Groups of Thach That District, Hanoi City

The soil of Thach That district, Hanoi city is divided into 4 soil groups with 8 soil types. The yellowish red soil group occupies the largest area with 6,033.71ha, accounting for 32.69% of total natural area. The Fluvisols group occupies the 2nd largest area wiith 3,670.82ha or 19.89 % of total natural area. The swampy soil and peat soil group, and deposit valley soil group have lowest area with 0.25% and 0.19% of total natural area of the district, respectively.The texture of yellowish red soil group varies from sandy loam to light clay and from slightly acidic to very acidic. CEC varies from low to medium. The content of total and available nutrients is quite high in the top soil layer but lower in subsoil layers. The Fluvisols group’s reaction is from mederately acidic to slightly acidic; the soil nutrient content varies from medium to quite rich in the top soil layer. CEC and exchangeable bases ranges from medium to quite high. The swampy soil and peat soil group has strong gley layer; the soil structure is destroyed, soil pH is from acidic to very acidic. The soil nutrient content varies from quite high to high. The deposit valley soil group varies from acidic to very acidic. Soil nutrient content, CEC and exchangeable base content are low, soil texture varies from light loam to medium loam.