Missouri National Resources Inventory (NRI)

The summary results presented in the Missouri NRI tables are derived from the 1997 NRI and the 2003 Annual NRI. The NRI is a series of natural resource inventories conducted by the U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service. The NRI is a scientifically based, longitudinal panel survey of the Nation’s soil, water and related resources, designed to assess conditions and trends. The NRI was conducted on a five-year cycle from1982 to 1997, but is now collected annually. In Missouri, the five-year cycle collected data from 8,700 sites; Missouri’s annual data collection occurs for slightly less than 25 percent of these same sample sites. The 1997 NRI provides a unique, consistent database constructed specifically to estimate 5-, 10- and 15-year trends on nonfederal lands for four points in time – 1982, 1987, 1992 and 1997. The 2003 Annual NRI statistically updated the 1997 NRI results with data collected during 2000 – 2002.

Missouri data for the 1997 NRI were collected for 8,700 locations, formerly called Primary Sample Units (PSUs) and now referred to as segments. In Missouri, the typical segment is a 160 acre tract. Within each segment, data are collected for up to three points. There are 26,000 permanent segment point locations in Missouri. The 1982 data collection involved on-site visits to each segment point and reviews of field office records. Data collection for 1987, 1992 and 1997 relied on USDA’s Farm Services Agency 35mm color compliance aerial slides and field office records. Revised standards and protocols were developed nationally by NRCS in collaboration with the Statistical Laboratory at Iowa State University and implemented for the 1997 NRI. Oversight and management of data-gathering were assigned to 21 regional units nationwide. These units, called Inventory Collection and Coordination Sites (ICCSs) were established according to regional land use patterns and state allocations of resources. The ICCS in Ames, Iowa oversaw data collection for Iowa and Missouri from 1997 to 2003. From 2004 onward, Missouri data collection has been managed from the NRCS Central Remote Sensing Laboratory (CRSL) located in Ft. Worth, Texas.

In 1998, NRCS initiated a five year transition to the annual inventory process. NRCS policy has been modified to ensure that the annual process is science based and that quality assurance protocols are implemented and monitored at national, regional and local levels. The Annual NRI inventory is part of an evolving resource inventory methodology that includes developing a multi-agency integrated inventory approach, incorporation of a wider variety of tools for assessment of resource health and further development of analysis capabilities to support policy analysis and program implementation. The five year transition period, ending with data collection during the summer of 2003, involved small, annual “special” inventories based on field office records, FSA compliance aerial photography and NRCS large scale, color aerial photography.

NRI data release procedures have been impacted by the implementation of annual data collection because the scale of NRI estimates is affected by the reduced sample sizes. Estimates for a particular level of geography are only released when they meet NRI statistical standards and are scientifically credible in accordance with NRCS policy and Office of Management and Budget (OMB) and United States Department of Agriculture (USDA) Quality of Information Guidelines.

The 2003 Annual NRI data are suitable for national, regional and state level analyses. Selected state level estimates are reported here. These results will be supplemented with additional estimates that will compare net change and land cover/use dynamics with previous inventories. Until these supplemental estimates are released, direct comparisons between 1997 and 2003 NRI estimates to determine change or trends will produce erroneous results. Updated sub-state level data, comparable to the 1997 NRI data, are much in demand and efforts are underway to develop the statistical protocols for constructing a sub-state level database for the Annual NRI process.

Missouri’s Annual NRI features a yearly inventory of approximately 2,125 segments. Each sample unit requires the collection of supporting field office information and photo interpretation as part of the data collection process. All field office and on-site data gathering is coordinated through Missouri’s NRCS Area Resource Soil Scientists and the State Resource Inventory Coordinator.

The annual sample is divided into two major types of segments:

• Core Sample – About 1,214 segments have been observed annually from 2000 and used for short-term trend determination.

• Rotation Sample – About 911 segments last observed prior to 2000.

The Missouri NRI is currently using scanned 9”x9” color aerial photography with a contact scale of 1:7,920 (1 inch = 666 ft.) for photo interpretation-based data collection. This high quality analog source photography has a ground sample distance of less than 1 foot. The USDA Farm Services Agency’s Aerial Photography Field Office (APFO) provides contract administration and film inspection services for all the NRI photography acquired nationwide.

1997 NRI Missouri data can be obtained several ways. National tables are available from the National NRI Web site. This site also has instructions for ordering a 1997 NRI CD-ROM. This CD is NOT a compilation of tables of estimates, but provides actual “raw data” that needs to be manipulated in a database management system with statistical software to generate estimates. The Missouri NRCS will not provide copies of the CD to external customers. Additionally, the State NRCS staff has access to the NRI Online Analysis System (OASys) to produce customized estimates that include standard errors.

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