The Green Revolution (GR) refers to the use of nitrogen fertilizer to increase agricultural crop yields. Although credited with reducing starvation in many countries, GR also caused adverse environmental effects from greenhouse gas emissions and eutrophication. These adverse environmental effects have led some to suggest that we need a greener revolution or GR-2.0 with improved environmental performance. One possible approach would be to increase nitrogen-use efficiency (NUE) in US agriculture. This study quantifies the effects of increased NUE on 1) national agricultural economy using a simulation model of US agriculture and 2) regional water quality effects using a biogeochemical model for the Arkansas-White-Red river basin. National economic effects are reported for NUE increases of 10%, 20%, 50%, and 100%, while regional water quality effects are estimated for a 20% NUE improvement scenario in the Arkansas-White-Red river basin. Simulating a 20% increase in NUE in row crops is shown to reduce N requirements by 1.4 million tonnes y-1 and increase farmer net profits by 1.6% ($743 million) per year over the baseline by 2026. For each 10% increase in NUE, annual farm revenues for commodity crops increased over the baseline by approximately $350 million per year by 2026. Changes in crop prices and land-use relative to the baseline are less than 2%. Results from the biogeochemical model of the Arkansas-White-Red river basin suggest that a 20% increase in NUE corresponds to a 5.8% reduction in nitrate loadings to freshwaters. Higher reductions occur in agricultural watersheds. The value of these reductions, estimated as the avoided cost of water treatment, is approximately $43 ha-1, for a total of $8,310,848. After estimating the social value of increased NUE, we conclude with a discussion of potential strategies to increase efficiency and the research needed to achieve this goal. These include perennialization of the agricultural landscape (bioenergy crops), genetic crop improvement, targeted fertilizer application, and manipulation of the plant-root microbiome.