Comparison of farm production input/output ratios to two land classification systems

ABSTRACT:

A quantitative comparison was made of the relationship between crop production input/output ratios and the U.S. Department of Agriculture's Land Capability Classification System and the Storie Index on three study areas (22,000 acres) in California's San Joaquin Valley. When input and output data were aggregated for five crops (alfalfa, corn, cotton, sugar beets, and wheat) over three years, calculated input/output ratios were significantly lower for higher class lands (between capability classes 1 and 3) than lower class lands (between capability classes 3 and 6). Significant differences remained when reclamation of the farmland was accounted for. Storie indices between 60 and 100 had lower but statistically insignificant lower input/output ratios than indices less than 60, both before and after reclamation. The individual (disaggregated) crop data for alfalfa, corn, cotton, sugar beets, and wheat showed that land in the higher classes and with higher indices had lower input/output ratios more often than the lower rated soils (before and after reclamation). These data support the intuitive feeling of soil scientists and land managers that there is an economic rationale for protecting higher quality lands as opposed to depending on the conversion to agriculture of lower quality lands for food production.