~ 4475 ~ The Pharma Innovation Journal 2022; SP-11(7): 4475-4480 ISSN (E): 2277-7695 ISSN (P): 2349-8242 NAAS Rating: 5.23 TPI 2022; SP-11(7): 4475-4480 © 2022 TPI www.thepharmajournal.com Received: 02-05-2022 Accepted: 07-06-2022 Mohammad Saud PG Scholar, Department of Agronomy, Agricultural College and Research Institute, TNAU, Killikulam, Tamil Nadu, India M Joseph Associate Professor, Department of Agronomy, Agricultural College and Research Institute, TNAU, Madurai, Tamil Nadu, India M Hemalatha Professor, Department of Agronomy, Agricultural College and Research Institute, TNAU, Madurai, Tamil Nadu, India D Rajakumar Assistant Professor, Department of Agronomy, Agricultural College and Research Institute, TNAU, Killikulam, Tamil Nadu, India S Jothimani Professor, Department of Soil Science and Agricultural Chemistry, Agricultural College and Research Institute, TNAU, Killikulam S Srinivasan Associate Professor, Department of Agronomy, Agricultural College and Research Institute, TNAU, Killikulam, Tamil Nadu, India Corresponding Author Mohammad Saud PG Scholar, Department of Agronomy, Agricultural College and Research Institute, TNAU, Killikulam, Tamil Nadu, India Effect of bio organic fertilizers (BoF) with nano urea spray on nitrogen economy of rice Mohammad Saud, M Joseph, M Hemalatha, D Rajakumar, S Jothimani and S Srinivasan Abstract The field experiment was carried out at Agricultural College and Research Institute, Killikulam as summer rice in 2021-2022 for the management of nutrients in wet seeded rice by using the combination of both organic and inorganic sources of nutrients. The different nitrogen sources utilized in the experimental study were STCR based N application through conventional urea, liquid Nano urea as foliar spray at critical stages of rice and Bio Organic Fertilizer (BoF). The BoF was prepared by the combination of Rice Husk Biochar (RHB), vermicompost, rock phosphate and microbial consortia. The combination of both organic and inorganic source of nutrients excelled over the other treatments. The treatment combination of STCR-N, Liquid nano urea as foliar spray and Bio Organic fertilizer (BoF) (T13) has the more plant height, a greater number of productive tillers, greater yield and higher B:C ratio among the other treatments. Keywords: STCR N, bio organic fertilizers (BoF), liquid nano urea, growth and yield, wet seeded rice 1. Introduction Rice (Oryza sativa L.) is the world’s most significant cereal crop, feeding over half of the world’s population. It covers around 155 million hectares (M ha) of area. It is cultivated from below 6 feet from sea level (as in Kerala, India) to 2700 feet above sea level in the Himalayas (Pathak et al., 2021) [12] . Total production and productivity of rice in Tamil Nadu in 2020-2021 is 6.8 t ha -1 and 3379 kg ha -1 , respectively. (India stat, 2022). Due to labour diversion to non- agricultural industries, there is a severe scarcity of human labour and a high pay rate during the transplanting season in all rice growing locations. In the face of a severe labour scarcity, the conventional method of manual transplanting becomes more difficult to assure timely planting with optimal seedling age, resulting in transplanting delays, lower yield, and lower profit. To avoid the challenges of laborious transplanting, direct seeding with a drum seeder can be used instead (Ramulu et al., 2020) [14] . Chemical fertiliser uses needs striking a balance between agricultural yield and long-term environmental sustainability. Inadequate chemical fertiliser use might suggest environmental damage (Zhen et al., 2005; 2006) [19-20] . Nitrogenous fertilisers are the most common fertiliser utilised in Indian soils. The nitrogenous type of macronutrient is favoured in fertilizer application (Venugopal, 2004; Sharma and Thaker, 2011) [18, 15] . Combined manure and appropriate chemical fertiliser application improve soil health by altering soil organic carbon content and microbial and enzyme activity (Dhiman et al., 2019 & Ozlu et al., 2019) [2, 11] . Biochar has been found to improve soil chemical characteristics by neutralising pH and boosting total nitrogen, available phosphorous, and exchangeable cation contents, CEC, and base saturation, while decreasing exchangeable Al ion levels, which inhibit root development (Ogawa and Okimori, 2010) [10] . However during the recent past Nano fertilizers have unique properties that improve plant performance in terms of high absorption, increased production, increased photosynthesis, and large expansion of the surface area of the leaves. Application of Nano urea at a rate of 2 - 4 ml per litre of water at critical stages of crop growth stimulates crop response, meets nutritional requirements and enhances nutrients availability. It is quickly absorbed by the plant leaves due to its Nano size (Singh et al., 2021) [] . Furthermore, regulated fertiliser release helps to reduce eutrophication and contamination of water resources (Kumar et al., 2020). Therefore, there is need to optimize the nitrogen use application in the rice crop by utilizing the use of different levels of nitrogen fertilizers based on the STCR and use of Nano urea, Bio Organic fertilizers. Thus, a study on “effect of Bio Organic fertilizers (BoF) with nano urea spray on growth and yield of rice” was conducted.