Data Collection
Agricultural Production Survey: June 2021 (Final)
Methodology
Period-specific information
Survey information
This release contains final results from the 2021 Agricultural Production Survey. These final figures are at regional level.
The 2021 survey was part of the current programme of agricultural production statistics that started in 2002. Previous censuses were held in 2002, 2007, 2012 and 2017, with annual sample surveys in 2003–06, 2008–11, 2013–16, 2018, 2019 and 2020.
Responses from farmers and foresters in the 2021 Agricultural Production Survey resulted in an estimated eligible population of 49,300 geographic locations.
2021 questionnaire changes (from 2020)
Horticulture – we did not include questions on the area of fruit trees and vines planted, and the area of vegetables and other horticulture crops harvested.
Irrigation – we did not include questions on area actually irrigated.
Effluent management – we did not include questions on effluent management systems.
Other farming practices – we did not include questions on formal farm nutrient planning documents used by the farm.
Cultivation, direct drilling and pasture renewal – we did not include questions on land area on the farm that was cultivated or direct drilled for any purpose.
Sample design
For the 2021 Agricultural Production Survey, we used a stratified sample design to select a sample from the population. In selecting this sample, we stratified the population by regional council area, ANZSIC06 group, and size group.
We determined the size groups as follows:
- For businesses that had previously responded to one or more of the agricultural production censuses or surveys since 2002, we used the most-recent production data to form size groups. The variables used covered a range of livestock and cropping variables. Typically, three size groups were formed: small, medium, and large.
- For new businesses or businesses that had not responded to any of the 2017 to 2020 agricultural collections, a random sample was taken.
The 2021 survey had a sample size of 30,200 geographic locations.
We optimised the 2021 sample design to produce a specified sampling error for certain combinations of key variables and regions, but not all. Given the dynamic nature of the agricultural sector, the sample errors for 2021 may sometimes be smaller or larger than planned, particularly for sectors that change rapidly.
2021 sampling error and imputation levels
Sampling error and imputation levels for the 2021 Agricultural Production Survey
| Description | Relative sampling errors at 95% confidence interval (%) | % of total estimate imputed |
|---|---|---|
| Calves born alive to dairy heifers/cows | 4 | 30 |
| Dairy cows and heifers, in milk or calf | 4 | 29 |
| Total dairy cattle | 4 | 28 |
| Calves born alive to beef heifers/cows | 3 | 23 |
| Beef cows and heifers in calf (age 1–2 years) | 9 | 22 |
| Beef cows and heifers in calf (aged 2 years and over) | 3 | 23 |
| Total beef cattle | 3 | 23 |
| Lambs born to ewe hoggets | 6 | 19 |
| Lambs born to ewes | 3 | 22 |
| Total lambs | 3 | 21 |
| Ewe hoggets put to ram | 6 | 19 |
| Breeding ewes (2-tooth and older) put to ram | 3 | 22 |
| Total sheep | 3 | 21 |
| Fawns born on the farm | 5 | 15 |
| Female deer mated | 6 | 15 |
| Total deer | 6 | 16 |
| Breeding sows (aged 1 year and over) | 1 | 3 |
| Mated gilts | 1 | 0 |
| Total pigs | 0 | 1 |
| Wheat tonnage harvested | 5 | 15 |
| Wheat area harvested (hectares) | 5 | 15 |
| Barley tonnage harvested | 7 | 20 |
| Barley area harvested (hectares) | 8 | 20 |
| Oat grain tonnage harvested | 13 | 19 |
| Oat grain area harvested (hectares) | 18 | 20 |
| Maize grain tonnage harvested | 13 | 19 |
| Maize grain area harvested (hectares) | 13 | 19 |
Response rates
The estimated proportion of eligible businesses that responded to the 2021 Agricultural Production Survey for this final release was 80 percent.
General information
About the estimates
Figures in this release are rounded. We calculate all percentages in this release using unrounded figures. The figures from the agricultural production surveys may differ from those produced from other sources, such as the National Exotic Forestry Description Survey produced by the Ministry for Primary Industries, the Stock Number Survey from Beef and Lamb New Zealand Limited, and Dairy Statistics from Livestock Improvement Corporation Limited. These surveys use different survey frames and designs.
When converting livestock numbers into stock units, for the various livestock types and class, stock unit conversion ratios from Beef and Lamb New Zealand were used as a guide. These are also known as the ‘Economic Service Conversions’ and can be found in the definitions section of the Beef and Lamb New Zealand benchmarking tool.
Population frame
The agricultural production surveys include all units identified on Statistics NZ's Business Register as having agricultural activity. The Business Register is a list of businesses in New Zealand, based on their registration for goods and services tax (GST) with Inland Revenue.
The compulsory registration level for GST is $60,000, so there is a partial and unquantifiable coverage of units below this level.
Survey population
The survey population for the agricultural production surveys is all businesses engaged in 'agricultural production activity' (including livestock, cropping, horticulture, and forestry), or which own land intended for agricultural activity. The survey population includes businesses engaged in agriculture or forestry production as a secondary activity.
Industries in scope
The survey population specifically includes businesses classified to the following ANZSIC06 codes:
- A01 Agriculture
- A0301 Forestry (excluding native forestry).
It also includes parts of:
- L671200 Non-residential property operators
- M691000 Scientific research services (agriculture-related research that involves land holding (excluding universities))
- P802300 Combined primary and secondary education (agricultural high school operation)
- P802400 Special school education (special needs education involving agricultural production activity)
- P810200 Higher education (agriculture-related research undertaken by universities that involves land holding)
- R912100 Horse and dog racing administration and track operation
- R912900 Other horse and dog racing activities (racehorse training and racing stables operations)
- R892200 Nature reserves and conservation parks operation.
The survey population specifically excludes:
- A019300 Beekeeping
- part of A019900 Other livestock farming nec (worm farming, pet breeding, dog breeding, cat breeding, bird breeding (except poultry, game birds, ostriches, and emus))
- A017100 Poultry meat (except growers who also produce eggs for human consumption).
Population changes
For the 2002 Agricultural Production Census, we sourced the population from the Business Business Register and the Inland Revenue Client Register. We checked these sources against industry lists and AgriBase to ensure all large units were included in the population.
After the 2002 Census, we use the Business Register for the census and survey populations.
Survey content changes
Over the years, we have changed the core information we gather in agricultural production collections.
Since 2002, these collections have gathered information on livestock and arable farming, horticulture, and forestry with the following exception:
In 2004, 2006, 2008, 2010, 2013, 2015, 2016, 2018 and 2021 the surveys collected information on livestock and arable farming, and forestry (we did not collect horticulture production information).
Stats NZ no longer collects information or compiles statistics relating to forestry production. These statistics can be found on the MPI website. Please note, Stats NZ does continue to collect information and compile statistics relating to forestry land use.
Past questionnaire changes
Fawns
Since the 2005 survey, the data relates to fawns born on the farm that were alive at four months. In 2003 and 2004, data related to fawns weaned on the farm. In 2002, data related to fawns born on the farm. The change took industry recommendations into account.
Deer
Deer figures since the 2004 survey are not directly comparable with 2002 and 2003 figures. Improvements we made to the questions about deer in the 2004, 2005, and 2006 surveys have resulted in improved deer number estimates. While it is not possible to quantify the exact extent of the previous under coverage, we estimate an undercount of about 70,000 deer at 30 June 2002, and 50,000 at 30 June 2003.
Reliability of sample survey estimates
This release contains statistics from the 2002–2021 agricultural production collections. All results from these collections are subject to non-sampling error, and sampling error.
Non-sampling error arises from bias in the patterns of response and non-response, inaccuracies in reporting by respondents, and errors in recording and classifying data. Non-sampling error comprises coverage error, measurement error (which arise from respondents, questionnaires, and collection methods), non-response error, and processing error. We use procedures to detect and minimise these types of error, but they may still occur and are not easy to quantify.
Sampling error occurs because we base inferences about the entire population on information obtained from only a sample of that population. As 2003–06, 2008–11, 2013–16, 2018–21 collections are sample surveys, not censuses, the results from these collections are also subject to sampling error.
Imputation
We impute values for farmers and foresters who do not return a completed questionnaire. Imputation involves replacing missing items with values based on other information available.
The method of imputation we use is random 'hot deck' imputation.
The Agriculture Production Survey uses random hot deck imputation. Using this method, we replace missing values of one or more variables for a non-respondent with observed values from a respondent with similar characteristics. The imputation class is formed from common characteristics such as regional council area, ANZSIC06 group, and production data from previous years. We randomly assign each non-respondent to a respondent in the same imputation cell, and the farm production data of the respondent is copied across to the non-respondent.
To improve the imputation process, we remove respondents with uncharacteristically high levels of agricultural activity from their respective imputation cells. It is unlikely that any of the non-respondents would have similar characteristics to them.
Confidentiality
Data collected and information contained in this release must conform to the provisions of the Statistics Act 1975. Published information must maintain the confidentiality of individual respondents. Prior to 2017 figures in tables affected by these provisions are denoted by ‘C’. Since 2017 confidentiality has been applied to agricultural statistics using an input perturbation method, which involves adding noise to data at an individual farm level. Figures in output tables no longer have to be replaced with ‘C’s.
Quality suppression
Data with high sample errors or imputation levels are suppressed and are indicated by 'S' in the table.
More information
See more information about the Agricultural Production Survey
Statistics in this release have been produced in accordance with the Official Statistics System principles and protocols for producers of Tier 1 statistics for quality. They conform to the Statistics NZ Methodological Standard for Reporting of Data Quality.
Liability
While all care and diligence has been used in processing, analysing, and extracting data and information in this publication, Statistics NZ gives no warranty it is error-free and will not be liable for any loss or damage suffered by the use directly, or indirectly, of the information in this publication.
Timing
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