Advances in Agronomy

DONALD L. SPARKS is the Unidel S. Hallock du Pont Chair and Francis Alison Professor at the University of Delaware. He is internationally recognized for his research in the areas of kinetics of biogeochemical processes and surface chemistry of natural materials. His research has focused on fate and transport of trace metals in soil and water, soil remediation, water quality, and carbon sequestration in soils. Dr. Sparks is the author of two previous editions of Environmental Soil Chemistry and more than 350 refereed papers and book chapters. He is fellow of five scientific societies, and he has been the recipient of major awards and lectureships including the Geochemistry Medal from the American Chemical Society, the Liebig Medal from the International Union of Soil Sciences, the Einstein Professorship from the Chinese Academy of Sciences and the Philippe Duchaufour Medal from the European Geosciences Union. Dr. Sparks served as president of the Soil Science Society of America and the International Union of Soil Sciences, has served on advisory committees for several national laboratories and national and international centers and institutes, and served as chair of the U.S. National Academy of Sciences (NAS) Committee for Soil Sciences and other NAS Committees.

• 1. Elevated CO2 in semi-arid cropping systems: A synthesis of research from the Australian Grains Free Air CO2 Enrichmen (AGFACE) research program Glenn J. Fitzgerald, Michael Tausz, Roger Armstrong, Joe Panozzo, Piotr Trębicki, Mahabubur Mollah, Sabine Tausz-Posch, Cassandra Walker, James G. Nuttall, Maryse Bourgault, Markus L€ow, Debra Partington, Clayton R. Butterly, Shu Kee Lam, Robert M. Norton, and Garry J. O'Leary2. Simultaneous effects of legume cultivation on carbon and nitrogen accumulation in soil Ahmad Latif Virk, Bai-Jian Lin, Zheng-Rong Kan, Jian-Ying Qi, Yash Pal Dang, Rattan Lal, Xin Zhao, and Hai-Lin Zhang3. Growing small grains organically in the semiarid West: A review of markets and management practices to optimize productivity and sustainability Nicole Tautges, Kristy Borrelli, Jessica Goldberger, Stephen Machado, E.P. Fuerst, Diana Roberts, and Ian Burke4. Principles and applications of topography in precision agriculture Ahmed Harb Rabia, Jasmine Neupane, Zhe Lin, Katie Lewis, Guofeng Cao, and Wenxuan Guo5. Retention of heavy metals by dredged sediments and their management following land applicationRichard J. Haynes and Ya-Feng Zhou6. Genetic diversity for developing climate-resilient wheatsto achieve food security goals Shabir H. Wani, Hanif Khan, Adnan Riaz, Dinesh Chandra Joshi, Waseem Hussain, Maneet Rana, Anuj Kumar, Naveenkumar Athiyannan, Dharmendra Singh, Niaz Ali, Manjit S. Kang, Mahjabeen Tariq, Rumana Keyani, Fatima Khalid, Muhammad Jamil, Abdul Aziz Napar, Sanjaya Rajaram, and A. Mujeeb-Kazi7. A century of subclover: Lessons for sustainable intensification from a historical review of innovations in subterranean clover seed production W.M. Moss, P.G.H. Nichols, K.J. Foster, M.H. Ryan, W. Erskine, and A.L. Guzzomi