The root density of plants with depth follows exponential or the Lindley distribution in the presence of outliers generated from a uniform distribution. In this article, we estimate the parameters of the Lindley distribution in the presence of outliers generated from a uniform distribution based on the moment, maximum likelihood, least squares, weighted least squares, percentile, Cramer-von-Mises, and Anderson-Darling methods and mixture estimator of moment and maximum likelihood. These methods of estimation are compared. Also, the estimators of the parameters of Lindley-uniform contaminated distribution are compared with the corresponding estimators of exponential-uniform contaminated distribution, which was presented by Dixit and Nasiri, Metron, 59(3-4), 187-198 (2001). Furthermore, an analysis of an actual example of the root length of plants is presented for illustrative purposes. It is concluded that the Lindley-uniform contaminated distribution is more appropriate than the exponential-uniform contaminated distribution to model the root density of plants.