Assessment of soil physico-chemical and biological properties as influenced by different biomanures under organic cotton production

An agronomic investigation was carried out to assess the soil physico-chemical and biological properties as influenced by different biomanures under organic cotton production at experimental field, Centre for Organic Agriculture Research and Training, Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, during kharif season of 2019–2020 and 2020–2021. The topography of experimental field was uniform and fairly leveled. The soil of experimental plot was medium and black in color with fair drainage and clayey in texture, low in available nitrogen, medium in available phosphorous and high in available potassium. The experimental data recorded during both successive year revealed that there was no significant results observed in relation to field capacity, permanent wilting point, bulk density and uptake of micronutrients such as Zn, Cu, Fe and Mn. However, the results also showed the significant soil available micronutrients, viz. Zn (0.98 and 0.93 mg kg−1), Cu (3.28 and 3.27 mg kg−1), Fe (7.74 and 6.83 mg kg−1) and Mn (5.88 and 5.57 mg kg−1), soil microbial biomass carbon recorded at flowering stage (217.97 and 202.59 µg g−1 soil) and harvest stage (189.72 and 177.82 µg g−1 soil), soil microbial biomass nitrogen at flowering stage (48.29 and 40.39 µg g−1 soil) and at harvest stage (46.78 and 34.62 µg g−1 soil) and dehydrogenese activity (32.45 and 32.27 µg TPF g−1 24 h−1) and at harvest stage (25.99 and 23.85 µg TPF g−1 24 h−1) with vermiwash @ 10% applied through drenching in combination with soil application of compost @ 3 t ha−1 and neem cake @ 500 kg ha−1 during 2019–2020 and 2020–2021, respectively.