The Center for Environmental Farming Systems (CEFS) is dedicated to farming systems that are environmentally, economically, and socially sustainable. Established in 1994 at the North Carolina Department of Agriculture and Consumer Services (NCDACS) Cherry Farm near Goldsboro, N.C.; CEFS operations extend over a land area of about 800 ha (2000 acres) [400 ha (1000 acres) cleared]. This unique center is a partnership among North Carolina State University (NCSU), North Carolina Agriculture and Technical State University (NCATSU), NCDACS, nongovernmental organizations (NGOs), other state and federal agencies, farmers and citizens. Long-term approaches that integrate the broad range of factors involved in agricultural systems are the focus of the Farming Systems Research Unit. The goal is to provide the empirical framework to address landscape-scale issues that impact long-run sustainability of North Carolina's agriculture. To this end, data collection and analyses include soil parameters (biological, chemical, physical), pests and predators (weeds, insects and disease), crop factors (growth, yield, and quality), economic factors, and energy issues. Five systems are being compared: a successional ecosystem, a plantation forestry-woodlot, an integrated crop-animal production system, an organic production system, and a cash-grain [best management practice (BMP)] cropping system. An interdisciplinary team of scientistsfrom the College of Agriculture and Life Sciences at NCSU and NCATSU, along with individuals from the NCDACS, NGO representatives, and farmers are collaborating in this endeavor. Experimental design and protocol are discussed, in addition to challenges and opportunities in designing and implementing long-term farming systems trials.