This dataset contains data from filtered waters taken from a tile drain system from a long-standing enhanced rock weathering experiment at the University of Illinois Energy Farm, Urbana-Champaign. Further details relating to the experimental design are available in the following papers: Beerling et al., 2024; Kantola et al., 2023. The data are from 4 experimental plots (each 3.9 ha in size) and 2 crop types, with 1 control and 1 treatment for each crop. One crop is an experimental bioenergy crop (Miscanthus grass), and the other is corn (maize) and soybean rotation. The tile drain waters are collected using an automated sampling system, and on occasion, samples were taken directly from the tile drain system for "in situ" analysis of time-critical species. All waters were filtered to <0.45 µm. Major cations and some trace elements and major anions were measured on the tile train waters collected via the automated sampling system triggered by water flow through the tile drain system. Alkalinity, dissolved inorganic carbon, dissolved organic carbon, total dissolved nitrogen and nutrient analysis were measured on the "in situ" samples. All analysis was carried out at the University of Southampton following methods outlined in Larkin et al., 2022, apart from pH, EC and temperature measurements on the in situ samples, which were carried out onsite at the University of Illinois. For further details, please contact the authors. References mentioned Beerling, D.J., Epihov, D.Z., Kantola, I.B., Masters, M.D., Reershemius, T., Planavsky, N.J., Reinhard, C.T., Jordan, J.S., Thorne, S.J., Weber, J., Val Martin, M., Freckleton, R.P., Hartley, S.E., James, R.H., Pearce, C.R., DeLucia, E.H., Banwart, S.A., 2024. Enhanced weathering in the US Corn Belt delivers carbon removal with agronomic benefits. Proc. Natl. Acad. Sci. 121, e2319436121. https://doi.org/10.1073/pnas.2319436121 Kantola, I.B., Blanc-Betes, E., Masters, M.D., Chang, E., Marklein, A., Moore, C.E., von Haden, A., Bernacchi, C.J., Wolf, A., Epihov, D.Z., Beerling, D.J., DeLucia, E.H., 2023. Improved net carbon budgets in the US Midwest through direct measured impacts of enhanced weathering. Glob. Change Biol. 29, 7012–7028. https://doi.org/10.1111/gcb.16903 Larkin, C.S., Andrews, M.G., Pearce, C.R., Yeong, K.L., Beerling, D.J., Bellamy, J., Benedick, S., Freckleton, R.P., Goring-Harford, H., Sadekar, S., James, R.H., 2022. Quantification of CO2 removal in a large-scale enhanced weathering field trial on an oil palm plantation in Sabah, Malaysia. Front. Clim. 4.