RESEARCH ARTICLE Effects of co-composting of farm manure and biochar on plant growth and carbon mineralization in an alkaline soil Muhammad Farooq Qayyum 1 & Fatima Liaquat 1 & Rabia Abdur Rehman 1 & Mehreen Gul 1 & Muhammad Zafar ul Hye 1 & Muhammad Rizwan 2 & Muhammad Zia ur Rehaman 3 Received: 24 June 2017 /Accepted: 13 September 2017 # Springer-Verlag GmbH Germany 2017 Abstract In the present study, the effects of co-composts of biochar (BC) and farm manure (FM) on the growth of wheat (Triticum aestivum L.) and carbon mineralization in an alka- line soil were investigated. The co-composts of FM and BC were prepared at various ratios (FM 100 :BC 0 , FM 75 :BC 25 , FM 50 :BC 50 , FM 25 :BC 75 , FM 0 :BC 100 ) using aboveground piles and were used in two separate experiments conducted simultaneously. In the plant growth trial, prepared co- composts were applied at a rate of 2% w/w and wheat was grown at two fertilizer levels (half and full) until maturity. In the incubation experiment, same treatments were used and carbon mineralization was studied over a period of 79 days. The priming effect and net CO 2 efflux were calculated using CO 2 release data. Analysis of postincubation soil showed no significant effect of treatments on the pH of soil. However, electrical conductivity and organic matter were significantly influenced by all treatments. The increasing BC ratio in the compost reduced the carbon mineralization in soil in a dose- additive manner. Increase in BC proportion in composts (FM 50 :BC 50 , FM 25 :BC 75 , FM 0 :BC 100 ) stabilized the native carbon of the soil and caused negative priming effect (-1.9, -5.6, and -8.48%, respectively). Regarding plant growth, the results showed an enhancement in the grain yield with the application of compost than control. Total nitrogen (N), phos- phorus, and potassium (K) contents of the soil were also in- creased by the application of compost than control (un- amended soil). Significantly higher N and K concentrations in wheat plants were also examined when soil was treated with compost than control. The use of compost with half fertilizer was better in increasing grain yield, especially with higher BC proportion in the compost than FM. Keywords Organicamendments . Wheat . Pyrolysis . Carbon sequestration Introduction Composting is considered a sustainable and environmental friendly approach for the safe utilization of solid organic wastes such as farm manure and trash of crops (Amlinger et al. 2007). Usually, composts are applied to get equivalent amounts of nutrients but that requires a large amount of appli- cation rates. Increase in organic matter and vegetable produc- tion are seen in previous research at different levels (22.5, 56, and 112 t ha -1 ) of compost application (Maynard 2005). Some reports stated that application of composts improved the soil physical, chemical, and biological as well as yield of crops compared to chemical fertilizers on sustainable basis (Bulluck et al. 2002). Mineralization of compost in the soil results in nutrient release and soil quality enhancement. The useful ef- fects of application of composted organic materials on soils are very extensively recognized all over the world (Amlinger et al. 2007; Lillenberg et al. 2010). Total organic matter con- tents, microbial activity, and nutrient release are also increased with the application of composts (Tandy et al. 2009). Compost improves the physicochemical properties of soils such as pH, Responsible editor: Yi-ping Chen * Muhammad Rizwan mrazi1532@yahoo.com 1 Department of Soil Science, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan 2 Department of Environmental Sciences and Engineering, Government College University Faisalabad, Faisalabad 38000, Pakistan 3 Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad, Pakistan Environ Sci Pollut Res DOI 10.1007/s11356-017-0227-4