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else," Bartell said. "Those programs might also be suitable for modification to use for looking at issues of genetically modified crops.”

Two speakers at the workshop described long-running monitoring programs that are carried out by the US government. Each has something to offer those who would design ecological monitoring programs for genetically modified crops.

Warren Lee, of USDA, described the natural-resources inventory, begun after passage of the Rural Development Act of 1972, which required USDA to assess the conditions and trends of soil, water, and related resources and report to Congress at intervals not to exceed 5 years. The inventory uses both remote sensing and onsite data collection to gather information about major land-resources areas and watershed levels. Because it is not feasible to track information on every bit of land in the United States, the inventory uses a sampling method that is statistically designed to give representative information about land use from data on a small percentage of the total land.

“We have 300,000 primary sample units across the United States,” Lee said, and most of the units contain three sample points at which data is drawn. The data describe the land not just at the point but within a specific distance from the point, and each point is classified into one of 69 categories depending on the use of the land and its cover: water, grass, forest, and so on. In addition, the inventory gathers a huge amount of other information, such as who owns the land, habitat composition, conservation practices, and soil characteristics and erosion.

The most important lesson from the natural-resources inventory, Lee said, is the necessity of knowing what you are trying to do before you get started. “We really need to understand what we are trying to understand. We need well-defined needs and well-defined requirements: Where are we going to collect the information? What are we going to collect? How is it going to be collected? How will it be used and analyzed?” Beyond that, he said, paying attention to the specific details of data collection is essential. “We want valid, compatible, and consistent data, and that demands training, technical support, data-collection quality-assurance instructions, checks and evaluations, accurate interpretation and classification, and quality, quality, quality.”

USDA also collects data on farms across the United States with its Agricultural Research Management Studies. The surveys have three main objectives, said Jorge Fernandez-Cornejo, an economist at USDA's Economic Research Service: “first, to gather information about agricultural production, resource use, input use, and farm practices; second, to determine the cost of production; and third, to determine farmers' net income and financial situation.”

The surveys gather data about farms in nine categories, including

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