Abstract

• In the present work, biosolids were prepared from dairy sludges. Dairy sludge was treated to form biosolids by processes such as dewatering, sludge pasteurization, anaerobic digestion, aerobic digestion, composting, and storage. The dairy biosolid fertilizer, D1 contained only dairy biosolid and D2 contained the weight ratios of (1:1:1) of dairy biosolid, rice husk ash and cocopeat. Physicochemical properties and micro- and macro nutrients of dairy biosolids fertilizers were qualitatively and quantitatively determined by EDXRF, AAS methods and other conventional methods. By using dairy biosolids fertilizer, a field experiment was conducted to test with mustards. The field experiment was laid out using a randomized complete block design (RCBD), with six treatments (T1-T6). Physicochemical parameters and micro-macro nutrients of soil samples before sowing and after harvesting were analyzed. The highest yield, 9.36 ton/ac, was achieved from the mustard treated only with dairy biosolid. The results from the study indicated that the prepared biosolid fertilizers can effectively be used for the growth and production of mustard.