Note that the data published in the 2002 State of the Nation’s Ecosystems Report as well as the 2003 and 2005 Web-Only Updates have been superseded by the 2008 Report and thus should be used with caution. For the most recent data, purchase the 2008 Report from Island Press.

The Indicator

This indicator presents ratios of certain major inputs identified and quantified by the U.S. Department of Agriculture (USDA) to total agricultural outputs, also as quantified by USDA. The intent is to report the amount of inputs needed to produce a unit of output, because the quantities of, and tradeoffs between, individual inputs (such as pesticides and fertilizer) are important. For example, if decreasing amounts of fertilizer are required to produce a unit of output, this has implications for the cost of production (fertilizer is a significant cost) and for off-farm environmental impacts (excess fertilizer can contribute to water pollution).

The Data

Data Source: Data came from Agricultural Productivity in the United States published by USDA’s Economic Research Service (ERS).

Data Collection Methodology: The output data represent all agricultural outputs, including animals and animal products (meat animals, dairy products, poultry, and eggs) and crops (food grains, feed crops, oilseed crops, sugar crops, cotton and cotton seed, vegetables and melons, and fruit and tree nuts). Aggregation of multiple outputs or inputs into a single index often requires assumptions about the comparability of unlike things––adding tons of corn to tons of strawberries would be nonsensical. USDA economists use an approach that involves determining the adjusted price of a given output, which is multiplied by the output quantity, so that all outputs can be added together into the single value shown here. ERS developed a similar scheme for adding inputs together; however, because the focus in this indicator is on changes in different inputs as well as the overall amount of inputs, the individual inputs are presented here. The yearly quantity of each input has been adjusted to some extent by ERS to reflect the changes in quality. For example, similar results can now be achieved with smaller quantities of pesticides. Thus, a larger quantity of less effective pesticide might be treated as equal to a smaller quantity of a more effective pesticide. The same is true for the other inputs, such as labor, whose quantities have been quality- adjusted over time.

Data Manipulation: Each input has been divided by the total farm output for that year. The data from ERS are all relative to a given year (1948) and are not reported as actual quantities. Because the focus of this report is on 1950–2000, we chose the midpoint (1975) as a more appropriate index year. Because of this, data (inputs and outputs) were simply divided by the 1975 value. All input data were then divided by the value of total outputs for any given year to produce the data shown in the figure.

Data Access: The data are available at http://www.ers.usda.gov/publications/aib740/; a more detailed version of the data is available at http://www.ers.usda.gov/data/sdp/view.asp?f=inputs/98003/.

2003 Web Site Update: Data for 1997-1999 were obtained directly from ERS and can be downloaded from http://www.ers.usda.gov/data/agproductivity.