Current Journal of Applied Science and Technology

A field experiment was conducted at the farm of Cotton Research Unit, Central Research Station, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, during kharif season 2015-16 to study the effect of organic cotton on biological properties of vertisols. The experiment was laid out in randomized block design with 3 replications and 10 treatments comprising organic sources viz. (T₁ – Farm yard manure (FYM) @ 5 t ha^-1, T₂ -  vermicompost @ 2.5 t ha^-1, T₃ - FYM @10 t ha^-1, T₄ - vermicompost @ 5 t ha^-1, T₅ - In-situ green manuring with sunhemp, T₆ - Castor cake @ 500 kg ha^-1, T₇ - FYM (source of 15 kg P₂O₅) + green manuring with  sunhemp, T₇ - FYM (source of 15 kg P₂O₅) + green manuring with  sunhemp, T₈ - Neem cake @ 500 kg ha^-1, T₉  - FYM 5 t ha^-1 + Neem cake @ 500 kg ha^-1 and  T₁₀ - Absolute Control). Results revealed that application of FYM @ 10 t ha^-1 recorded significantly highest bacterial, fungal population during flowering and boll bursting stages of cotton. However, highest actinomycetes population was recorded by the application of vermicompost @ 5 t ha^-1 at flowering stage and FYM @ 10 t ha^-1 at boll bursting stage of cotton. Significantly highest seed cotton yield was obtained with the concentrated organic manure i.e.  Neem cake @ 500 kg ha^-1 and remained at par with Castor cake @ 500 kg ha^-1, FYM 5 t ha^-1 + Neem cake @ 500 kg ha^-1.