Seedlings of black locust (Robinia pseudoacacia L.) were inoculated with compatible rhizobia and irrigated twice each week with solution containing either 50 or 150 mg nitrogen/L. Leaching fraction treatments of 0, 0.2, or 0.4 were maintained for 6 weeks. Seedlings supplied 50 mg nitrogen/L grew poorly compared co planes supplied 150 mg nitrogen/L regardless of leaching fraction. Dry masses of shoots and of entire planes were lower for seedlings in the 0 and 0.2 leaching fraction treatments compared with chose in the 0.4 treatment. Neither leaching fraction nor applied nitrogen concentration appeared co affect the number of nodules per plant, but nodule diameter seemed greater on planes irrigated with the more dilute solution. We conclude that reducing leaching can reduce shoot growth of containerized black locust, but the monetary and environmental benefits of lower water and fertilizer use should be considered before the commercial significance of the growth reduction is judged
