Alvenäs, G., and M. Stenberg. 1995.
Problems in estimating soil water content by TDR measurements. 
Paper in the Proceedings of the Symposium: Time-Domain Reflectometry Applications in Soil Science, (Foulum, Denmark, Sept 16, 1994) SP Report No. 11, June, Vol. 3, pp. 121-123.
(posted July 2, 1996)

Since 1992, researchers at the Department of Soil Sciences, SUAS, have used the TDR technique for estimation of soil water content. Water contents in soils ranging from sand to heavy clay have been determined over a ranges of temperature and moisture regimes. However, we have experienced several problems when evaluating the data and we would like them to be subjects to discussion. We have noticed a dependence of temperature on the estimated soil water content. In particular, the daily oscillation in estimated soil water content has been found to be synchronized with daily temperature oscillation. The difference between the highest and lowest water contents during a clear day could be as high as 5%.