Soil Fertility and Nutrient management (1+1)

Factors affecting decomposition

 
• The most important conditions that affect the rate of decomposition are

  1. Temperature: Cold periods retard the organic matter decomposition and there will be more accumulation of organic matter on the top soil compared to that of warm climates. The most suitable temperature is 30-40 degree celcius for proper decomposition.
  2. Soil moisture: Near or slightly wetter than field capacity moisture conditions are most favorable for decomposition. About 60-75 % water holding capacity (WHC) is optimum.
  3. Soil pH: 6-8 pH or neutral pH is required for optimum growth of microorganisms. Bacteria at 6 - 7 pH, Actinomycetes is more at pH 8 -10, Algae pH of 5.5 - 7.5, Fungi- pH 4.0, Protozoa – pH 3.0
  4. Nutrients: Lack of nutrients, particularly N reduces microbial growth and it slows decomposition. Addition of nutrients by N fertilizers (urea) increases the speed of decomposition
  5. Soil texture: Soils higher in clays tend to retain larger amounts of humus, other condition being equal.
  6. Aeration: Good aeration increases the rate of decomposition and supply oxygen.
  7. Nature of plant matter: composition and age of plants and vegetations affect much their decomposition. It is fast in young, tender, and juicy material, But slow with more cellulose and hemicelluloses content.