Both long-term soil fertility plots and greenhouse plantings were used to train professional agronomists to diagnose specific nutrient deficiencies. The field plots have been managed to result in specific nutrient deficiencies that include N, P, and K; as well as underlimed and overlimed plots; and plots to which optimum and excess rates of poultry litter have been added. This field is typically managed with research funding as a RCBD with 4 replications, but we periodically use the site for training and plant a different crop in each experimental block. In 2006, corn, cotton, soybean, and peanut were planted. Greenhouse sand culture was used to grow these 4 crops plus tobacco and rice in nutrient solutions that were either complete or missing N, P, K, S, Mg, Cu, Mn, Zn, B; or that had excess Zn. Specimens were photographed at stages with notable deficiencies and also exhibited during the field crop training event. The 33 attendees included cooperative extension agents and other professional agronomists, participation was voluntary and was approved for 4 hours of CCA continuing education units. Anonymous pre- and post-testing was used to evaluate learning. Mean test scores were higher after the training, but due to small sample sizes quantitative assessment of effectiveness was not reliable. Participant comments were generally highly favorable, although several expressed reluctance to submit to testing.