There are two independent sets of data collected and published by the National Agricultural Statistics Service (NASS) which contain county crop and livestock information.
(1) The Census of Agriculture is conducted every five years and, by definition, is a complete accounting of the crops and livestock produced on all farms and ranches and current inventories of livestock on all farms for the Census year.
(2) NASS prepares and publishes crop annual county data to support the USDA farm program (barley, corn, cotton, oats, peanuts, rice, sorghum, soybeans, and wheat). County data are prepared and published for additional commodities through our cooperator program (hay, minor oil seeds, and minor pulses), with each of the state departments of agriculture. The cooperator program also supports the annual livestock inventory data by county. The annual county data are based on reports from a sample of farms and ranches.
(Note: A national program for cattle inventory was initiated in 2001.)
Agricultural Statistics Districts (ASD) are defined groupings of counties in each State, by geography, climate, and cropping practices. The geographic attributes include soil type, terrain, and elevation (mountains). The basic components of climate are mean temperature, annual precipitation and length of growing season. These factors influence the crops grown, the need to conserve soil moisture, and the use of irrigation (cropping practices). District estimates were discontinued in 2020.
What are the geographic boundaries of the Counties and Districts?
The Census of Agriculture, taken every five years, is a complete count of U.S. farms and ranches and the people who operate them. The Census looks at land use and ownership, operator characteristics, production practices, income and expenditures and many other areas. For America’s farmers and ranchers, the Census of Agriculture is their voice, their future and their responsibility.
NASS's annual program focuses on agricultural production for mainstream crops, livestock and associated inventories. The program is based on a series of sample surveys to collect farm level data to produce the State and U.S. crop forecasts and estimates published in the NASS Agricultural Statistics Board reports. NASS produces approximately 400 reports each year with information released on a weekly, monthly, quarterly, or annual basis depending on the commodity program. The largest single survey NASS conducts each year is the June Agricultural Survey. This survey has two parts - a list sample frame and an area sample frame.
The area frame, which is essentially the entire land mass of the United States, ensures the inclusion of the entire U.S. farm population. The land in each State is classified into land use categories by intensity of cultivation using a variety of map products, satellite imagery, and computer software packages. These land use classifications range from intensively cultivated areas, to marginally cultivated or grazing areas, to urban areas. The land in each use category is then divided into segments ranging from about one square mile in cultivated areas to 0.1 square mile in urban areas. About 10,000 sample segments are selected, at varying rates, by land use classification. Approximately 50,000 operators who farm in these segments will be interviewed during the June Agricultural Survey.
The list frame contains the names and addresses of all known farms and ranches NASS has obtained from various sources. Each farm is classified by operation characteristics such as number of corn acres or number of cattle. Large farms (e.g., Iowa farms with more than 5,000 acres of cropland) are sampled at high rates, while small farms (e.g., farms with less than 50 acres of cropland) are randomly selected at very low rates. A sample of about 75,000 farms is selected for each of the quarterly Crops and Hogs (June, September, December and March) surveys. Sample sizes for the January Cattle and Sheep surveys are 50,000 and 10,000 farms, respectively.
Data from the area and list frame samples are expanded and combined using multiple-frame statistical methodology which ensures that all farms are represented in the summary totals and that each farm is included only once. These samples are designed to produce estimates at the State and/or U.S. levels only.
The end-of-season December survey is supplemented with a mailing to a county sample of about 300,000 farm operators (~15 percent of the 2.19 million farms) to collect information to support the County Data program. The responses from this supplemental sample are combined with those from the December Quarterly Survey and aggregated to a County Summary.
The county data are "assembled" starting from the State estimate and working back to the county and are published by Headquarters to Quick Stats. The following is a brief outline of the process to produce the annual county data, using corn for grain as an example. The State Corn for Grain estimate, published in the Crop Production Summary each January, is the total to which the counties must add. The County Summary, in combination with administrative data from various sources (other USDA agencies, cotton ginners, etc.), is the basis for the annual county data for crop acreage, yield and production, and livestock inventories.
Because NASS uses sample surveys, it may not be possible to publish information for all counties. In most cases, unpublished (minor) counties are grouped to a All Other Counties total within each state. In addition to minor counties, concentrations of animals (or birds) may limit the publication of livestock inventories for some counties to avoid disclosure of individual operations.
National Program. The national portion of the County Data program focuses on the major grains and row crop commodities. Beginning in 2001, cattle inventory was added to the national program. Cooperative agreements with other USDA agencies and general support for the Farm Program provide the funding for this group of commodities.
State (Cooperator) Program. NASS maintains cooperative agreements with each State Department of Agriculture and/or Land Grant University to conduct a joint statistics program that supports both the national and State needs. The cooperative agreements eliminate duplication of effort and produce a cost efficient information program. The livestock and poultry (cattle, hogs, chickens, etc.) inventories and hay, minor pulses, and select vegetables are estimated by the Regional Offices and published to Quick Stats by Headquarters. Local (State) funding may limit information availability for a specie(s), commodity, data item(s) or year(s), including data for some major producing States.
The livestock county data and data for hay, minor pulses, and select vegetables are prepared as required by each State's Department of Agriculture program. Local (State) funding may limit data availability for a specie(s), commodity, data item(s) or year(s), including some major production States. All available data are included in the On-Line-Database.
If data are needed for all counties for a selected commodity, the Census of Agriculture most likely will have data for All States. However, some counties may not be published to avoid disclosure of individual operations. The general guideline for determining disclosure is less than three (3) reports for the item or one operations has more than 60 percent of the total. The Census county data are available on CD-ROM as a custom query database.
The States with no cooperator program are listed by species. The data items available vary by State based on the cooperator program.
Cattle & Calves and Milk Production: California, Colorado, Connecticut, Delaware, Iowa, Maine, Massachusetts, New Hampshire, Rhode Island, South Dakota, and Vermont.
Program Change: NASS instituted a National program for major cattle producing states beginning with the 2001 Inventory. Several of the states listed above will have annual county data beginning with the year 2001.
Hogs and Pigs: California, Colorado, Connecticut, Delaware, Florida, Idaho, Iowa, Louisiana, Maine, Maryland, Massachusetts, Nevada, New Hampshire, Rhode Island, South Dakota, Utah, Vermont, and Wyoming.
Sheep & Lambs and Wool Production: Alabama, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Indiana, Iowa, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, North Carolina, Rhode Island, South Carolina, South Dakota, Tennessee, and Vermont.
Chickens and Egg Production: Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Louisiana, Maine, Maryland, Massachusetts, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New Jersey, New York, North Dakota, Ohio, Rhode Island, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, and Wyoming.
NASS has a policy of reviewing data the year after initial publication. Based on new administrative data, States may revise the previous year of county data. These changes are made at the same time the "current year" data are prepared. Following the Census of Agriculture, every five years, NASS reviews the data for intervening years and revises data when appropriate. Generally, revisions are small and a limited number of States and years are changed for any commodity.