Pedosphere 25(5): 686–695, 2015 ISSN 1002-0160/CN 32-1315/P c ⃝ 2015 Soil Science Society of China Published by Elsevier B.V. and Science Press Influences of Biochar and Biochar-Mineral Complex on Mycorrhizal Colonisation and Nutrition of Wheat and Sorghum Paul BLACKWELL 1 , Stephen JOSEPH 2,3,4 , Paul MUNROE 2 , Hossain M. ANAWAR 5 , Paul STORER 6 , Robert J. GILKES 5 and Zakaria M. SOLAIMAN 7∗ 1 Department of Agriculture and Food Western Australia, Geraldton Regional Office, Geraldton, WA 6530 (Australia) 2 School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia) 3 Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia) 4 University of Wollongong, Wollongong, NSW 2522 (Australia) 5 School of Earth and Environment and UWA Institute of Agriculture, The University of Western Australia, Crawley, WA 6009 (Australia) 6 Australian Mineral Fertilisers Pty Ltd., Tenterden, WA 6322 (Australia) 7 Soil Biology and Molecular Ecology Group, School of Earth and Environment and UWA Institute of Agriculture, The University of Western Australia, Crawley, WA 6009 (Australia) (Received May 21, 2015; revised July 20, 2015) ABSTRACT The high price of synthetic fertilisers and the price barrier for biochar as a soil amendment have encouraged the exploration of using biochar in fertiliser replacement formulations. Biochars coupled with fertilisers can be applied at lower application rates to achieve benefits in plant growth and nutrition, as well as soil biological fertility. It is necessary to evaluate the use of biochar as a fertiliser substitute. Therefore, this study investigated the comparative influences of biochars, including Acacia saligna (AS), Simcoa jarrah (SJ) and Wundowie jarrah (WJ), mineral fertiliser with microbes (MF + M), biochar-mineral complex (BMC) and their combination on mycorrhizal colonisation, growth and nutrition of wheat in a glasshouse experiment and sorghum in field conditions. BMC + MF + M treatment produced higher mycorrhizal colonisation than MF + M alone, indicating that BMC had a significant role in increasing mycorrhizal colonisation. SJ (treated with acetic acid) and MF + M treatments, as well as AS + MF + M application, showed similar effects on mycorrhizal colonisation, but lower colonisation than the BMC + MF + M treatment. Overall, the BMC + MF + M treatment supported the maximum shoot, root and total plant dry weight followed by AS + MF + M and WJ + MF + M. The MF + M treatment had the maximum shoot N and K concentrations, while BMC + MF + M application had the maximum shoot P concentration. AS + MF + M and WJ + MF + M treatments supported the maximum N uptake by wheat shoots, while BMC + MF + M supported the maximum P uptake. The results showed that biochars and BMCs could increase mycorrhizal colonisation, plant growth and nutrient uptake of wheat, particularly N, P, K, S and Zn. The field experiment confirmed that BMC application at a rate of 300 kg ha −1 could increase the yield of irrigated sorghum on a loam soil and provide better applied P use efficiency compared to a water-soluble fertiliser alone. These results indicated that biochar-based fertilisers might increase the resilience and sustainability of dryland cropping in environments such as in Western Australia and warrant further field evaluation. Key Words: carbon sequestration, nutrient uptake, P use efficiency, soil biological fertility, wheat production Citation: Blackwell P, Joseph S, Munroe P, Anawar H M, Storer P, Gilkes R J, Solaiman Z M. 2015. Influences of biochar and biochar-mineral complex on mycorrhizal colonisation and nutrition of wheat and sorghum. Pedosphere. 25(5): 686–695. Biochar is a product of pyrolysis of either plant or animal biomass through heating at 300 to 600 ◦ C under partial exclusion of oxygen (Antal and Grønli, 2003), resulting in highly aromatic organic material with C concentrations of 400 to 800 g kg −1 (Lehmann et al., 2002; Lehmann and Rondon, 2006). Biochar is a variable charge organic material, with a relatively high surface area and pore volume, that has the potential to increase soil water-holding capacity, pH, cation ex- change capacity (CEC), surface sorption capacity, nu- trient content, and base saturation (Glaser et al., 2002; B´ elanger et al., 2004; Keech et al., 2005; Liang et al., 2006). These properties change in relation to the tem- perature of biochar formation and the feedstock used for biochar production (Gundale and DeLuca, 2006; Bornermann et al., 2007). The increased nutrient avai- lability to plants is the results of both the direct nutri- ent additions in biochar and greater nutrient retention against leaching (Lehmann et al., 2003), but it can al- so be an effect of changes in soil microbial dynamics (Lehmann and Rondon, 2006). Interactions between biochar, soil, microbes and plant roots may occur wi- thin a short period of time after application to the soil (Joseph et al., 2010). Biochars undergo dissolution-pre- ∗ Corresponding author. E-mail: zakaria.solaiman@uwa.edu.au.