Soil Fertility and Nutrient Management

Causes of soil acidity

1. Leaching of bases like Ca, Mg, Na etc., due to heavy rainfall
2. Acidic parent material like granite
3. Use of acid forming fertilizers like Urea and ammonium sulphate
4. Decomposition of organic matter leading to release of various organic acids
5. Continuous cultivation of crops leads to more absorption of basic cations form the soil
6. Acid rains containing sulphate and nitrate ions
7. Aluminium and Iron polymers- One Al species release 3 H+ ions upon step wise hydrolysis and similar reactions are possible with Fe3+ also.
8. Laterization, podzolization and accumulation of undecomposed organic matter under marshy conditions contribute to soil acidity.