summing across all States. The WRR estimates were 
obtained by summing the expanded data values for 
the portion of the sample falling into the WRR. 
RESPONDENT CONFIDENTIALITY 
In keeping with the provisions of Title 7 of the 
United States Code, no data are published that would 
disclose information about the operations of an 
individual farm or ranch. All tabulated data are 
subjeeted to an extensive diselosure review prior to 
publication. Any tabulated item that identifies data 
reported by a respondent or allows a respondent’s 
data to be aceurately estimated or derived, was 
suppressed and coded with a ‘D’. However, the 
number of farms reporting an item is not considered 
eonfidential information and is provided even though 
other information is withheld. 
DATA COMPARABILITY 
The 2013 Farm and Ranch Irrigation Survey data 
were weighted for incompleteness of the mail list. 
For Tables 7 through 18, 22, and 24 through 26, the 
State level FRIS data are not eomparable between 
the 2013 and 2008 surveys. In the 2013 survey, the 
data ineluded operations that reported hortieultural 
sales during the previous eensus year. In 2008, data 
for operations with hortieultural sales were ineluded 
in Chapter 2, Hortieultural Operations Data tables. 
To provide a measure of comparability, where 
possible, the published 2008 U.S. level data were 
adjusted to include the horticulture operations’ data. 
Differenees exist between the expanded results of the 
2013 Farm and Raneh Irrigation Survey and 
published data from the 2012 Census of Agrieulture. 
Some of these are as follows: 
1. The survey includes data only for operations 
that irrigated in both 2012 and 2013. 
Operations in some areas, especially the 
eastern States, irrigate intermittently aeeording 
to moisture needs. Operations with irrigation 
eapabilities may not irrigate depending on the 
amount of rainfall for a partieular year or 
geographic area. The number of operations that 
irrigated in 2012 but diseontinued irrigation in 
2013 is tabulated in Table 27 for all farms and 
in Table 44 for hortieultural operations by 
reason of discontinuanee. 
2012 Census of Agriculture 
USDA, National Agricultural Statistics Service 
2. Some operators reported that they had been 
miselassified as irrigators and did not irrigate 
in either 2012 or 2013. An estimated 9,522 
operations with 743,333 aeres irrigated were 
miselassified as irrigated in the 2012 Census of 
Agriculture. In addition to errors in proeessing 
census data, some operators misreported or 
misinterpreted the questions. Most of the 
operators misreporting irrigation in the 2012 
census reported irrigation of small aereages of 
vegetables, fruits and nuts, tobaeeo, field erops, 
or berries. 
3. Some respondents indieated they had retired, 
moved, sold or rented the land, ete., since 
2012. After analytieal review of the 2013 
receipts, an estimated 17,022 operations 
aeeounting for 2,107,745 aeres irrigated in 
2012, after expansion, were dropped from 
processing beeause they were no longer 
farming. Special care was taken with large 
operations to ensure that they were not 
erroneously dropped due to reorganization or 
name ehange rather than diseontinuing 
agricultural operations. 
4. New irrigators in 2013 (not ineluded in the 
2012 eensus) did not have a chanee of being 
seleeted in the sample and, therefore, were 
excluded from the survey. It is believed that the 
impact of new irrigators is probably minimal. 
This conelusion is supported by comparisons 
between the 2007 and 2012 Census of 
Agrieulture irrigation data whieh show little 
ehange in irrigated aeres. 
Table B shows aeres irrigated in the 2013 FRIS 
(expanded) eompared with U.S. totals from the 2012 
Census of Agriculture. The expanded survey 
aeeounts for 99.1 pereent of all land reported as 
irrigated in the 2012 eensus and all irrigation 
eharaeteristies assoeiated with that land. 
MEASURES OF SURVEY QUALITY 
The statisties in this report are estimates derived 
from a sample survey. There are two types of errors 
possible in an estimate-based sample survey: 
sampling and nonsampling. Sampling error is the 
error caused by observing only a sample instead of 
the entire population. The sampling error is subjeet 
Appendix A A - 3 
