Effect of Organic Sources on Biological Properties of Vertisols in Cotton

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.