Evaluating Of Green Manure, Lime, Wood Ash And Fre-Flooding In Improving Acid Sulphate Soil In Senegal
By Mike F Nzomo Mwikya
“Soil acidity” is the term used to express the quantity of hydrogen (H) and aluminum (AI) Cations (Positively charged ions) in soils. When levels of hydrogen and aluminum become too high and the soil becomes too acidic the soils negatively charged ions (CEC) becomes “clogged” with the positively charged hydrogen and aluminum and the nutrients needed for plant growth are pushed out. This is why root growth and plant development suffer when soil become too acidic.
Over time, soils also become acidic because calcium and magnesium-leach out because hydrogen is added to soils by decomposition of plant residue and organic matter, or because nitrification of ammonium occurs when fertilizer (UAN solution urea, ammonium nitrate, ammonium sulfate, anhydrous ammonia), manure or plant residues are added to the soil. Lime will neutralize these acidity components, hydrogen and ammonium. Soil PH is an indicator of soil acidity. Values below 7.0 are acidic and values above 7.0 are basic or alkaline. A soil with a PH of 5 is 10 times more acidic than soil with a PH of 6 and 100 times more acidic than soul with a PH of 7.0. Most plants grow in slightly acidic soils, so the goal of liming is not to raise the PH to neutral(7.0) but to avoid crop problems related to acidity.