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.
National, Regional and State Level Reporting
The annual estimates are accumulated and incorporated into interim national, regional and state reports. Annual reports replace preceding annual reports for analysis purposes. With each new inventory, the estimates for the previous inventory years are recalculated to reflect changes in inventory technologies and protocols. This ensures consistency for trend analysis when a sufficient amount of data has been collected through the annual inventory process. For example, the 2003 Annual NRI statistically updated the 1997 state-level results with data collected from 2000-2003 and is suitable for national, regional and state level analyses but only for 2003 conditions.
The 2007 NRI database provides nationally consistent data for the 25-year period 1982-2007; constructed specifically to estimate 5-, 10-, 15-, 20- and 25-year trends for six points in time: 1982, 1987, 1992, 1997, 2002 and 2007. The 2007 NRI database has been constructed from statistically updated data from 1982, 1987, 1992 and 1997 from the 1997 NRI and updated estimates from the Annual 2000- 2007 NRI Inventories. The 2007 NRI data are suitable for national, regional and state level analyses. Current state level estimates will be supplemented with additional estimates on soil erosion and land use as they become available.
Sub-State Level Reporting
Updated sub-state level estimates, comparable to the sub-state data reported from the 1997 NRI database are much in demand. Efforts are underway to develop the statistical protocols for constructing sub-state level estimates for selected data categories from the 2007 NRI database.