Integrated effect of organic manure and Azotobacter with inorganic fertilizer on soil properties, yield and quality of sugarcane plant-ratoon system under calcareous soil

Field experiment were conducted for two consecutive seasons on spring sugarcane plant-ratoon system to investigate the integrated effect of organics viz. bio-compost (BC) and bio-methaneated distillery effluent (BMDE) with Azotobacter on growth, yield, quality and soil fertility of sugarcane. The mean data revealed that number of millable cane (NMC), cane yield, and sugar yield varied significantly due to integrated use of organic and inorganic fertilizer with Azotobacter in combination both in plant and ratoon crops. The significant increase in number of millable cane (NMC), cane yield and sugar yield was recorded in the treatments receiving organic and inorganic fertilizer in combination with Azotobacter over control both in plant in ratoon crops. The mean data for NMC (70-98x103/ha), cane yield (61-80.4 t/ha) and sugar yield (7.13 - 9.75 t/ha) varied significantly. The highest number of NMC (98.90 X 103 ha-1), cane yield (80.40 t ha-1) and sugar yield (9.25 t ha-1) was recorded in treatment receiving 50% N + 100% PK through inorganic fertilizer and 50% N through BC with Azotobacter (@ 5kg/ha). The residual effect of treatment receiving organic and inorganic fertilizer in combination with Azotobacter was also pronounced on NMC (96.3 x 103 ha-1), yield (76.1 tha-1) and sugar yield (9.24 tha-1), However, treatment receiving 50% N through BMDE was found on par with application of 50% N through BMDE. Both the organic sources improved performance of sugarcane. The uptake of nutrients (NPK) by plant and ratoon followed the similar trend as cane yield. The treatment receiving RDF along with Azotobacter improved productivity of sugarcane significantly over control (RDF). However, the efficiency of Azotobacter was more pronounced under inorganic treated plots. The reduction in pH and increase in EC, organic carbon and available nutrients (NP&K) of soil was recorded in treatment receiving organics either through bio-compost or BMDE. The available-N content of soil increased in Azotobacter and organic treated plots. The result clearly indicated that integrated use of BC / BMDE along with Azotobacter improved fertility status of soil with improvement in population of microbes.