Dr Tim McLaren
Senior Lecturer Soil Science
School of Agriculture and Food Sustainability
+61 7 336 52128
Researcher biography
Dr McLaren graduated in 2009 with a Bachelor of Rural Science (Honours) from the University of New England, Armidale (NSW), Australia. He then completed a doctorate in soil science and cropping systems in 2013 (main supervisor, Associate Professor Dr Christopher Guppy) at the University of New England, followed by a three year postdoctoral research fellowship in soil science and grazing systems (main supervisor, Associate Professor Dr Ronald Smernik) at the University of Adelaide. From 2015 to 2021, Dr McLaren was a 'Senior Scientist' in the Group of Plant Nutrition under Professor Dr Emmanuel Frossard, at the Swiss Federal Institute of Technology (ETH) Zurich, Switzerland. In 2021, Dr McLaren returned to Australia and was appointed as a 'Senior Lecturer in Soil Science' at the University of Queensland.
The overall goal of Dr McLaren's work is to provide new insight on the biogeochemistry of nutrients that will lead to improved outcomes for agricultural and environmental contexts. In particular, he is interested in identifying the diversity of inorganic and organic forms of nutrients, and understanding the processes governing their flux in soil-plant systems. An important part of Dr McLaren's work has been the characterisation of organic matter, and understanding the processes governing the accumulation and depletion of nutrients within soil organic matter. In addition, Dr McLaren has gained much experience on understanding the fate of fertiliser in agroecosystems, and assessing different agronomic strategies to improve plant growth and fertiliser use efficiency, and decrease nutrient transfer to aquatic/marine ecosystems.
Dr McLaren's work has primarily focused on phosphorus, but also included sulfur, nitrogen, and carbon. It has involved a wide variety of analytical approaches, including radiotracers (P-33, S-35), stable isotopes (N-15), spectroscopy (NMR, PXRF, XANES), chromatography (size-exclusion), and 'wet' chemistry (e.g. sequential chemical fractionation and hypobromite oxidation). Research has involved laboratory, glasshouse, and field based experiments, a diversity of soil types, and various ecosystem contexts (e.g. cropping, pasture, and forests). Lastly, Dr McLaren has often worked in colloboration with a variety of stakeholders (e.g. primary producers, agronomists, and industry), and formed international colloborations with applied and fundamental scientists.
Book Chapters
McLaren, Timothy I. (2023). The use of radioactive isotopes to study soil pools and processes. Encyclopedia of soils in the environment. (pp. 96-106) edited by Michael J. Goss and Margaret Oliver. Amsterdam, Netherlands: Elsevier. doi: 10.1016/B978-0-12-822974-3.00258-5
McLaren, Timothy I. (2023). The use of radioactive isotopes to study soil pools and processes. Encyclopedia of Soils in the Environment. (pp. 96-106) edited by Michael J. Goss and Margaret Oliver. Amsterdam, Netherlands: Elsevier. doi: 10.1016/b978-0-12-822974-3.00258-5
McLaren, Timothy I., Smernik, Ronald J., McLaughlin, Michael J., Doolette, Ashlea L., Richardson, Alan E. and Frossard, Emmanuel (2020). The chemical nature of soil organic phosphorus: a critical review and global compilation of quantitative data. Advances in agronomy. (pp. 51-124) edited by Donald L. Sparks. Cambridge, MA, United States: Academic Press. doi: 10.1016/bs.agron.2019.10.001
Journal Articles
Li, Tong, Cui, Lizhen, Kuhnert, Matthias, McLaren, Timothy I., Pandey, Rajiv, Liu, Hongdou, Wang, Weijin, Xu, Zhihong, Xia, Anquan, Dalal, Ram C. and Dang, Yash P. (2024). A comprehensive review of soil organic carbon estimates: integrating remote sensing and machine learning technologies. Journal of Soils and Sediments. doi: 10.1007/s11368-024-03913-8
Li, Tong, Cui, Lizhen, Wu, Yu, McLaren, Timothy I., Xia, Anquan, Pandey, Rajiv, Liu, Hongdou, Wang, Weijin, Xu, Zhihong, Song, Xiufang, Dalal, Ram C. and Dang, Yash P. (2024). Soil Organic Carbon Estimation via Remote Sensing and Machine Learning Techniques: Global Topic Modeling and Research Trend Exploration. Remote Sensing, 16 (17) 3168, 3168. doi: 10.3390/rs16173168
Siegenthaler, Maja Barbara, McLaren, Timothy Ian, Frossard, Emmanuel and Tamburini, Federica (2024). Dual isotopic (33P and 18O) tracing and solution 31P NMR spectroscopy to reveal organic phosphorus synthesis in organic soil horizons. Soil Biology and Biochemistry, 197 109519, 109519. doi: 10.1016/j.soilbio.2024.109519
McKenna, Brigid A., Kopittke, Peter M., Bell, Michael J., Lombi, Enzo, Klysubun, Wantana, McLaren, Timothy I., Doolette, Casey L. and Meyer, Gregor (2024). Phosphorus availability and speciation in the fertosphere of three soils over 12 months. Geoderma, 447 116913, 1-10. doi: 10.1016/j.geoderma.2024.116913
Defterdarović, Jasmina, Filipović, Lana, Ondrašek, Gabrijel, Bogunović, Igor, Dugan, Ivan, Phogat, Vinod, He, Hailong, Rashti, Mehran Rezaei, Tavakkoli, Ehsan, Baumgartl, Thomas, Baghbani, Abolfazl, McLaren, Timothy I. and Filipović, Vilim (2024). Impact of Hillslope Agriculture on Soil Compaction and Seasonal Water Dynamics in a Temperate Vineyard. Land, 13 (5) 588, 588. doi: 10.3390/land13050588
Honvault, Nicolas, Faucon, Michel-Pierre, McLaren, Timothy, Houben, David, Frossard, Emmanuel and Oberson, Astrid (2024). Influence of cover crop residue traits on phosphorus availability and subsequent uptake by plants. Nutrient Cycling in Agroecosystems, 128 (2), 131-148. doi: 10.1007/s10705-023-10333-6
Li, Tong, Xia, Anquan, McLaren, Timothy I., Pandey, Rajiv, Xu, Zhihong, Liu, Hongdou, Manning, Sean, Madgett, Oli, Duncan, Sam, Rasmussen, Peter, Ruhnke, Florian, Yüzügüllü, Onur, Fajraoui, Noura, Beniwal, Deeksha, Chapman, Scott, Tsiminis, Georgios, Smith, Chaya, Dalal, Ram C. and Dang, Yash P. (2023). Preliminary results in innovative solutions for soil carbon estimation: integrating remote sensing, machine learning, and proximal sensing spectroscopy. Remote Sensing, 15 (23) 5571, 1-17. doi: 10.3390/rs15235571
Reusser, Jolanda E., Piccolo, Alessandro, Vinci, Giovanni, Savarese, Claudia, Cangemi, Silvana, Cozzolino, Vincenza, Verel, René, Frossard, Emmanuel and McLaren, Timothy I. (2023). Phosphorus species in sequentially extracted soil organic matter fractions. Geoderma, 429 116227, 1-12. doi: 10.1016/j.geoderma.2022.116227
Prüter, Julia, McLaren, Timothy I., Pätzig, Marlene, Hu, Yongfeng and Leinweber, Peter (2023). Phosphorus speciation along a soil to kettle hole transect: sequential P fractionation, P XANES, and 31P NMR spectroscopy. Geoderma, 429 116215, 1-13. doi: 10.1016/j.geoderma.2022.116215
Reusser, Jolanda E., Tamburini, Federica, Neal, Andrew L., Verel, René, Frossard, Emmanuel and McLaren, Timothy I. (2022). The molecular size continuum of soil organic phosphorus and its chemical associations. Geoderma, 412 115716, 115716. doi: 10.1016/j.geoderma.2022.115716
McLaren, Timothy I., Verel, René and Frossard, Emmanuel (2022). Soil phosphomonoesters in large molecular weight material comprise of multiple components. Soil Science Society of America Journal, 86 (2), 345-357. doi: 10.1002/saj2.20347
Neal, Andrew L., McLaren, Timothy, Campolino, Mariana Lourenco, Hughes, David, Coelho, Antonio Marcos, de Paula Lana, Ubiraci Gomes, Gomes, Eliane Aparecida and de Sousa, Sylvia Morais (2021). Crop type exerts greater influence upon rhizosphere phosphohydrolase gene abundance and phylogenetic diversity than phosphorus fertilization. FEMS Microbiology Ecology, 97 (4) fiab033. doi: 10.1093/femsec/fiab033
Alewell, Christine, Huang, Jen-How, McLaren, Timothy, Huber, Lea and Bunemann, Else K. (2021). Phosphorus retention in constructed wetlands enhanced by zeolite- and clinopyroxene-dominated lava sand. Hydrological Processes, 35 (2) e14040. doi: 10.1002/hyp.14040
Reusser, Jolanda E., Verel, René, Zindel, Daniel, Frossard, Emmanuel and McLaren, Timothy I. (2020). Identification of lower-order inositol phosphates (IP5 and IP4) in soil extracts as determined by hypobromite oxidation and solution 31P NMR spectroscopy. Biogeosciences, 17 (20), 5079-5095. doi: 10.5194/bg-17-5079-2020
Reusser, Jolanda E., Verel, René, Frossard, Emmanuel and McLaren, Timothy I. (2020). Quantitative measures of: Myo-IP6 in soil using solution 31P NMR spectroscopy and spectral deconvolution fitting including a broad signal. Environmental Science: Processes and Impacts, 22 (4), 1084-1094. doi: 10.1039/c9em00485h
McLaren, Timothy I., Smernik, Ronald J., McLaughlin, Michael J., McBeath, Therese M., McCaskill, Malcolm R., Robertson, Fiona A. and Simpson, Richard J. (2020). Soil phosphorus pools with addition of fertiliser phosphorus in a long-term grazing experiment. Nutrient Cycling in Agroecosystems, 116 (2), 151-164. doi: 10.1007/s10705-019-10035-y
Braun, Sabina, McLaren, Timothy I., Frossard, Emmanuel, Tuyishime, J. R. Marius, Börjesson, Gunnar and Gustafsson, Jon Petter (2020). Phosphorus desorption and isotope exchange kinetics in agricultural soils. Soil Use and Management, 38 (1) sum.12674, 1-13. doi: 10.1111/sum.12674
van der Bom, F. J.T., McLaren, T. I., Doolette, A. L., Magid, J., Frossard, E., Oberson, A. and Jensen, L. S. (2019). Influence of long-term phosphorus fertilisation history on the availability and chemical nature of soil phosphorus. Geoderma, 355 113909, 1-12. doi: 10.1016/j.geoderma.2019.113909
McLaren, Timothy I., Verel, René and Frossard, Emmanuel (2019). The structural composition of soil phosphomonoesters as determined by solution 31P NMR spectroscopy and transverse relaxation (T2) experiments. Geoderma, 345, 31-37. doi: 10.1016/j.geoderma.2019.03.015
Glæsner, Nadia, van der Bom, Frederik, Bruun, Sander, McLaren, Timothy, Larsen, Flemming Hofmann and Magid, Jakob (2019). Phosphorus characterization and plant availability in soil profiles after long-term urban waste application. Geoderma, 338, 136-144. doi: 10.1016/j.geoderma.2018.11.046
Andersson, Karl O., Tighe, Matthew K., Guppy, Christopher N., Milham, Paul J., McLaren, Timothy I., Schefe, Cassandra R., Lombi, Enzo, Lisle, Leanne M. and Klysubun, Wantana (2019). Transformation of calcium phosphates in alkaline Vertisols by acidified incubation. Environmental Science and Technology, 53 (17), 10131-10138. doi: 10.1021/acs.est.9b01565
Spain, Alister V., Tibbett, Mark, Ridd, Michael and McLaren, Timothy I. (2018). Phosphorus dynamics in a tropical forest soil restored after strip mining. Plant and Soil, 427 (1-2), 105-123. doi: 10.1007/s11104-018-3668-8
George, T. S., Giles, C. D., Menezes-Blackburn, D., Condron, L. M., Gama-Rodrigues, A. C., Jaisi, D., Lang, F., Neal, A. L., Stutter, M. I., Almeida, D. S., Bol, R., Cabugao, K. G., Celi, L., Cotner, J. B., Feng, G., Goll, D. S., Hallama, M., Krueger, J., Plassard, C., Rosling, A., Darch, T., Fraser, T., Giesler, R., Richardson, A. E., Tamburini, F., Shand, C. A., Lumsdon, D. G., Zhang, H., Blackwell, M. S.A. ... Haygarth, P. M. (2018). Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities. Plant and Soil, 427 (1-2), 191-208. doi: 10.1007/s11104-017-3391-x
George, T. S., Giles, C. D., Menezes-Blackburn, D., Condron, L. M., Gama-Rodrigues, A. C., Jaisi, D., Lang, F., Neal, A. L., Stutter, M. I., Almeida, D. S., Bol, R., Cabugao, K. G., Celi, L., Cotner, J. B., Feng, G., Goll, D. S., Hallama, M., Krueger, J., Plassard, C., Rosling, A., Darch, T., Fraser, T., Giesler, R., Richardson, A. E., Tamburini, F., Shand, C. A., Lumsdon, D. G., Zhang, H., Blackwell, M. S.A. ... Haygarth, P. M. (2018). Correction to: Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities (Plant and Soil, (2018), 427, 1-2, (191-208), 10.1007/s11104-017-3391-x). Plant and Soil, 427 (1-2), 209-211. doi: 10.1007/s11104-017-3488-2
Helfenstein, Julian, Jegminat, Jannes, McLaren, Timothy I. and Frossard, Emmanuel (2018). Soil solution phosphorus turnover: derivation, interpretation, and insights from a global compilation of isotope exchange kinetic studies. Biogeosciences, 15 (1), 105-114. doi: 10.5194/bg-15-105-2018
McLaren, Timothy I., McBeath, Therese M., Simpson, Richard J., Richardson, Alan E., Stefanski, Adam, Guppy, Christopher N., Smernik, Ronald J., Rivers, Colin, Johnston, Caroline and McLaughlin, Michael J. (2017). Direct recovery of 33P-labelled fertiliser phosphorus in subterranean clover (Trifolium subterraneum) pastures under field conditions – the role of agronomic management. Agriculture, Ecosystems and Environment, 246, 144-156. doi: 10.1016/j.agee.2017.05.029
McLaren, Timothy I., Smernik, Ronald J., Simpson, Richard J., McLaughlin, Michael J., McBeath, Therese M., Guppy, Christopher N. and Richardson, Alan E. (2017). The chemical nature of organic phosphorus that accumulates in fertilized soils of a temperate pasture as determined by solution 31P NMR spectroscopy. Journal of Plant Nutrition and Soil Science, 180 (1), 27-38. doi: 10.1002/jpln.201600076
Doolette, Ashlea L., Smernik, Ronald J. and McLaren, Timothy I. (2017). The composition of organic phosphorus in soils of the Snowy Mountains region of south-eastern Australia. Soil Research, 55 (1), 10-18. doi: 10.1071/SR16058
Andersson, Karl O., Tighe, Matthew K., Guppy, Christopher N., Milham, Paul J., McLaren, Timothy I., Schefe, Cassandra R. and Lombi, Enzo (2016). XANES demonstrates the release of calcium phosphates from alkaline vertisols to moderately acidified solution. Environmental Science and Technology, 50 (8), 4229-4237. doi: 10.1021/acs.est.5b04814
McLaren, Timothy I., McLaughlin, Michael J., McBeath, Therese M., Simpson, Richard J., Smernik, Ronald J., Guppy, Christopher N. and Richardson, Alan E. (2016). The fate of fertiliser P in soil under pasture and uptake by subterraneum clover – a field study using 33P-labelled single superphosphate. Plant and Soil, 401 (1-2), 23-38. doi: 10.1007/s11104-015-2610-6
Andersson, Karl O., Tighe, Matthew K., Guppy, Christopher N., Milham, Paul J. and McLaren, Timothy I. (2016). The release of phosphorus in alkaline vertic soils as influenced by pH and by anion and cation sinks. Geoderma, 264, 17-27. doi: 10.1016/j.geoderma.2015.10.001
Andersson, Karl O., Tighe, Matthew K., Guppy, Christopher N., Milham, Paul J. and McLaren, Timothy I. (2015). Incremental acidification reveals phosphorus release dynamics in alkaline vertic soils. Geoderma, 259-260, 35-44. doi: 10.1016/j.geoderma.2015.05.001
McLaren, Timothy I., Smernik, Ronald J., Simpson, Richard J., McLaughlin, Michael J., McBeath, Therese M., Guppy, Christopher N. and Richardson, Alan E. (2015). Spectral sensitivity of solution 31P NMR spectroscopy is improved by narrowing the soil to solution ratio to 1:4 for pasture soils of low organic P content. Geoderma, 257-258, 48-57. doi: 10.1016/j.geoderma.2015.02.004
McLaren, Timothy I., Smernik, Ronald J., McLaughlin, Mike J., McBeath, Therese M., Kirby, Jason K., Simpson, Richard J., Guppy, Christopher N., Doolette, Ashlea L. and Richardson, Alan E. (2015). Complex forms of soil organic phosphorus-a major component of soil phosphorus. Environmental Science and Technology, 49 (22), 13238-13245. doi: 10.1021/acs.est.5b02948
McLaren, T. I., Guppy, C. N., Tighe, M. K., Schefe, C. R., Flavel, R. J., Cowie, B. C.C. and Tadich, A. (2015). Validation of soil phosphate removal by alkaline and acidic reagents in a vertosol soil using XANES spectroscopy. Communications in Soil Science and Plant Analysis, 46 (16), 1998-2017. doi: 10.1080/00103624.2015.1048252
Mclaren, Timothy I., Simpson, Richard J., Mclaughlin, Michael J., Smernik, Ronald J., Mcbeath, Therese M., Guppy, Christopher N. and Richardson, Alan E. (2015). An assessment of various measures of soil phosphorus and the net accumulation of phosphorus in fertilized soils under pasture. Journal of Plant Nutrition and Soil Science, 178 (4), 543-554. doi: 10.1002/jpln.201400657
McLaren, Timothy I., Smernik, Ronald J., Guppy, Christopher N., Bell, Mike J. and Tighe, Matthew K. (2014). The organic P composition of vertisols as determined by 31P NMR spectroscopy. Soil Science Society of America Journal, 78 (6), 1893-1902. doi: 10.2136/sssaj2014.04.0139
Stanley, John N., Baqir, Hussein Ali and Mclaren, Timothy I. (2014). Effect on larval growth of adding finely ground silicon-bearing minerals (wollastonite or olivine) to artificial diets for Helicoverpa spp. (Lepidoptera: Noctuidae). Austral Entomology, 53 (4), 436-443. doi: 10.1111/aen.12086
McLaren, Timothy, Bell, Michael, Rochester, Ian, Guppy, Christopher, Tighe, Matthew and Flavel, Richard (2013). Growth and phosphorus uptake of faba bean and cotton are related to Colwell-P concentrations in the subsoil of Vertosols. Crop and Pasture Science, 64 (8), 825-833. doi: 10.1071/CP13025
McLaren, Timothy I., Guppy, Christopher N. and Tighe, Matthew K. (2012). A rapid and nondestructive plant nutrient analysis using portable X-ray fluorescence. Soil Science Society of America Journal, 76 (4), 1446-1453. doi: 10.2136/sssaj2011.0355
McLaren, Timothy I., Guppy, Christopher N., Tighe, Matthew K., Forster, Nicola, Grave, Peter, Lisle, Leanne M. and Bennett, John W. (2012). Rapid, nondestructive total elemental analysis of vertisol soils using portable X-ray fluorescence. Soil Science Society of America Journal, 76 (4), 1436-1445. doi: 10.2136/sssaj2011.0354
Conference Papers
Devoto, F., Reynolds-Massey-Reed, S., Segura, Pinzon C., Bell, M., Mclaren, T., Awale, R., Camino, C., Bange, M., Woodgate, W., Chapman, S. and Potgieter, A. B. (2024). Insights in the ability of high-resolution narrow band multispectral and thermal sensors to estimate cotton production in Australia. 2024 IEEE International Geoscience and Remote Sensing Symposium, Athens, Greece, 7-12 July 2024. Piscataway, NJ, United States: IEEE. doi: 10.1109/igarss53475.2024.10642663
Schefe, Cassandra R., Barlow, Kirsten M., Robinson, Nathan J., Crawford, Douglas M., McLaren, Timothy I., Smernik, Ronald J., Croatto, George, Walsh, Ronald D. and Kitching, Matt (2015). 100 Years of superphosphate addition to pasture in an acid soil - Current nutrient status and future management. International Workshop on Soil Change Matters, Bendigo, VIC, Australia, 24-27 March 2014. Clayton, VIC, Australia: CSIRO Publishing. doi: 10.1071/SR14241
McLaren, Timothy I., Guppy, Christopher N., Tighe, Matthew K., Moody, Phil and Bell, Mike (2013). Dilute acid extraction is a useful indicator of the supply of slowly available phosphorus in Vertisols. Madison, WI, United States: Soil Science Society of America. doi: 10.2136/sssaj2013.05.0188
Data Collection
McLaren, Tim (2023). Wheat 2022 V1. The University of Queensland. (Dataset) doi: 10.48610/92b978e