OICC Press International Journal of Recycling of Organic Waste in Agriculture 2251-7715 15 1 2026 03 31 Equine Dung as an Organic Nitrogen Supplement in Compost Formulation for Cultivation of White Button Mushroom [Agaricus Bisporus J.E. Lange (Imbach)] 10.57647/ijrowa.2026.17359 EN Roohi Jan Division of Plant Pathology, Faculty of Agriculture, SKUAST-Jammu, Jammu and Kashmir, India https://orcid.org/0009-0009-7673-2367 Sachin Gupta Division of Plant Pathology, Faculty of Agriculture, SKUAST-Jammu, Jammu and Kashmir, India https://orcid.org/0000-0003-4711-9845 Sudheer Kumar Annepu ICAR-Indian Institute of Soil and Water Conservation, Research Center, Udhagamandalam, Tamil Nadu, India Moni Gupta Division of Biochemistry, Faculty of Basic Sciences, SKUAST-Jammu, Jammu and Kashmir, India https://orcid.org/0000-0003-0918-4996 Journal Article 2026 03 31 Purpose: The present study aimed to utilize the equine dung as an organic nitrogen supplement in commercial compost formulations for the cultivation of white button mushroom. Method: Four different compost formulations (C1 to C4) were prepared using wheat straw or in combination with paddy straw as the basic ligno-cellulosic substrate material. The initial nitrogen levels were maintained at 1.48–1.79% by incorporating various nitrogen enrichment materials such as chicken manure, equine dung, mustard oil cake and wheat bran. Results: The C4 compost formulation (composed of wheat straw – 150 kg, equine dung – 400 kg, mustard oil cake – 30 kg, wheat bran – 30 kg, gypsum – 25 kg, and urea – 6 kg) exhibited the highest biological efficiency of 18.20%, outperforming poultry manure-based compost formulations. Among the various physico-chemical properties of the matured compost, the C:N ratio was identified as a critical factor for achieving higher yields and an extended cropping period. Conclusion: The experimental findings demonstrate an environmentally sustainable approach for utilizing equine dung waste in a productive way to cultivate protein-rich food. This study highlights the potential of equine dung as a valuable component in compost formulations for white button mushroom production.  Highlights ·       Equine Dung as a Sustainable Nitrogen Source: Equine dung was successfully utilized as an organic nitrogen supplement in compost formulations, promoting sustainable and productive management of equine waste. ·       Enhanced Biological Efficiency: The compost, prepared using equine dung, mustard oil cake, wheat bran, gypsum, and urea, resulted in maximum biological efficiency of 18.20%, outperforming the commercial poultry manure-based formulations. ·       Optimized Nitrogen Levels for Yield: Initial nitrogen levels in compost formulations (1.48–1.79%) were optimized to support higher yields of white button mushroom (Agaricus bisporus). ·       Importance of C:N Ratio: Physico-chemical analysis highlighted that the C:N ratio of matured compost significantly influenced mushroom yield and cropping period. ·       Environmental and Nutritional Benefits: The study demonstrates an environmentally sustainable approach to converting equine dung waste into a productive resource for cultivating protein-rich white button mushrooms.