Most previous studies conducted to examine food barley production constraints in Ethiopia were single factor experiments and unsuitable to determine the relative importance of various factors and interactions among these factors. To develop sustainable food systems in regions with limited resources, it is essential to understand the relative importance of alternative production inputs and their interactions. A replicated 2(5) factorial experiment examined the effects of cultivar, fertilizer, weeding, fungicide, and seed dressing on food barley production under local and recommended practices at the Holetta Research Center in 1987 and 1988. Results indicate that poor soil fertility is a major constraint to food barley production followed by weed competition, then by shootfly incidence. Cultivar choice and fungicide spray appear to be relatively less important. A combination of higher input levels and their positive interactions demonstrated the beneficial effect of combining improved production practices in one cultural package where adequate resources are available. Future research needs to give high priority to improvement of soil fertility, minimum weed competition and use of landraces to develop resistant cultivars to shootfly and diseases. Special attention must be placed on those practices and systems that maximize the use of internal, renewable resources, and to convincing researchers, growers, and policy makers that long-term sustainability must take precedence over shortterm, single factor production enhancement initiatives.