sustainability of farming system in the exemplary farms

the sustainability of farming system (sofs) is considered to be an important principle in a broad concept of sustainable agriculture. variables affecting sofs include alternate crop farming (using nitrogen-fixing plants as alternate crops), utilizing farm animal manure, using plants and crop residues back into the soil system, and utilizing a variety of protective plowing schemes. overuse and persistent application of chemical fertilizers and insecticide beyond the recommended dose could adversely affect the sofs. the main purpose of this study was to measure the sofs in corn growers’ farms. the exemplary corn producers of fars province in iran (whose average yield was more than eight tons/hectar) made up the population of this study. a questionnaire was designed to collect the data for the study. this was a survey research and was a descriptive - corrolational type of study. the results indicated that 58 percent of farmers’ lands are both partially and totally unsustainable and 42 percent are considered to be sustainable. overuse of chemical fertilizers and insecticides are the most important features that make the system unsustainable. the sofs was highly correlated with the farmers’ average yield per hectar and a statistically significant relation was found between these two variables.