Agricultural research is susceptible to research deterioration due to biological, climatic, and economic forces. Research deteriorates as the base conditions it addresses change which leaves the resulting information or technology less effective, efficient, productive, and/or relevant. Maintenance research targets deterioration in an attempt to prevent any loss of previous gains. Maintenance research is in contrast to productivity enhancing research which attempts to increase efficiency or productivity beyond previously attained thresholds. In 1986, Adusei and Norton conducted a survey of agricultural scientists across the United States to measure the amount of commodity based agricultural research devoted to maintenance research (1990). They discovered roughly 35% of all agricultural research related to commodities was spent on maintenance research. A follow-up survey was conducted in 2008 to see if the proportion of maintenance research engaged in agricultural research had risen. In this survey, the amount of maintenance research in non-commodity based agricultural research was also measured. The percentage of agricultural commodity research engaged in maintenance research was found to have risen to roughly 41%. In contrast, the percentage of maintenance research in agricultural non-commodity research was found to be roughly 29%. An empirical model was developed to explain maintenance research expenditures. Agricultural research funding, climatic conditions, land degradation, pest and pathogen control, and agricultural production were thought to influence maintenance research expenditures. From these five categories, seven representative variables were included in the model. The model found each category except land degradation to have a statistically significant impact on maintenance research expenditures. / Master of Science