usdagov 8661742564 20130418-REE-RBN-5743

---

Size: 1870px × 1336px
Photo credit: © Nature and Science / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: agriculture, bio-challenge, biomass, building, carroll, conference, dc, department, economics, education, efficiency, energy, jamie, john, national, nature, park, patio, ree, renewable, research, science, states, states-israel, symposium, united, usda, washington, whitten