Farm structure survey - reference periods

Last updated: November 2026

This article outlines the reference periods laid down in the legislation governing the Farm Structure Survey (FSS) and the Integrated Farm Statistics (IFS). It examines comparability issues relating to reference periods across countries in farm statistics data collections and in relation to the legislative requirements. It also considers the comparability of national reference periods between different rounds of data collection. The article is part of an online publication of methodological articles dealing with farm structure statistics. The analysis and findings in this article are based on the information available in the national quality reports national quality reports.

Definitions of reference periods within the legislation - IFS 2020 and IFS 2023

The reference periods for the Integrated Farm Statistics for both 2020 and 2023 are laid down in Article 10 of Regulation (EU) 2018/1091, as follows:

Land variables: the use of land shall refer to the reference year. In the case of successive crops from the same piece of land, the land use shall refer to a crop harvested during the reference year, regardless of when that crop was sown.
Variables on irrigation and soil management practices: these shall refer to a 12-month period ending within the reference year. Each Member State shall set this period so that it covers the relevant production cycles.
Variables on livestock and animal housing: these shall refer to a common reference day within the reference year. The variables on manure management shall refer to a 12-month period including that day.
Labour force variables: these shall refer to a 12-month period ending on a reference day within the reference year.
Rural development measures: these shall refer to a 3-year period ending on 31 December of the reference year.
All other variables: these shall refer to a common reference day within the reference year.

Additionally, countries should ensure that the data for all modules reflect the situation in the reference year. However, for the modules regarding 'machinery and equipment', 'orchard' and 'vineyard', the legislation (Article 7 (4)) allows the data to be based on either the year immediately preceding or following the reference year.

For Greece and Portugal, Article 19 of the same regulation provides for derogations, where references to the year 2020 are replaced, if necessary, by references to the year 2019. Only Portugal used the derogation.

IFS 2023: comparability of reference periods across countries and with respect to the legislation

In general, countries applied the reference periods and reference days within the limits laid down in Article 10 of Regulation (EU) 2018/1091. However, there were considerable differences in the reference periods and reference days applied at national level. The analysis below sets out the national reference periods and reference days used in the IFS 2023, grouped by the category of variables covered.

For the following countries, the national reference periods and days comply with the Regulation: Belgium, Bulgaria, Czechia, Estonia, Ireland, Greece, Spain, France, Italy, Cyprus, Latvia, Lithuania, Luxembourg, Malta, Poland, Portugal, Romania, Slovenia, Slovakia, Finland, Sweden, Norway and Serbia.

Land variables

Table 1 presents an overview of the reference periods applied to land variables. The reference period under Regulation (EU) 2018/1091 was permitted from 1 January 2023 to 31 December 2023.

The earliest reference period was applied in Denmark (ending on 21 April 2023), and the latest was applied in Belgium, Germany, Ireland, Austria, Slovenia, Finland and Norway (ending on 31 December 2023).

Germany

For the orchards module, the calendar year 2022 was used. Data is based on the orchard survey of that year.

Irrigation and soil management variables

Deviations from the regulation as regards the reference period for these variables were noted for Denmark, Germany, Croatia, Hungary, the Netherlands and Austria. All other countries complied with the relevant provisions.

Denmark, Croatia and Hungary

In the case of Denmark, the reference period for the 'irrigation' module was the 12-month period ending on 14 June 2023. For Croatia and Hungary, it was the 12-month period ending 1 June 2023. As the main irrigation season typically occurs in autumn, the module reflects the situation in 2022. This is because fieldwork began in June 2023, at a time when farmers were not yet able to indicate how much irrigation would be carried out during the upcoming season.

Germany

For Germany, the reference period for the 'irrigation' module was the 2022 calendar year, in order to ensure comparability over time of the irrigated area variables.

Netherlands

For the Netherlands, the reference period for both the 'irrigation' module and the 'soil management practices' module was the 2022 calendar year. For the 'irrigation' module this deviation was necessary because farmers would not have been able to complete reliably the form between 1 March and 15 May 2023 to provide the information for the 2023 calendar year. Instead, farmers were asked to provide information for 2022. The same approach was applied to the 'soil management practices' module.

Austria

For Austria, the reference period for the 'irrigation' module was the 12-month period ending on 31 March 2023. As the survey began in April 2023, the only possible amount of irrigation volume and irrigated area that could be reported concerned the previous cropping period (2022). The farmers could not reliably state at the time of the survey how much they would irrigate during the upcoming season.

Livestock, animal housing and manure management variables

Regarding livestock variables, all reporting countries used a reference day between 1 January and 31 December 2023, in compliance with Regulation (EU) 2018/1091 (see Table 2).

The reference days applied for livestock characteristics ranged from 1 February 2023 in Luxembourg to 31 December 2023 in both Cyprus and Romania.

The comparability of the livestock data between countries is particularly sensitive because animal numbers may vary significantly depending on the season.

Labour force variables

Regarding the labour force variables, all reporting countries used a 12-month reference period ending on a reference day within the reference year, in compliance with Regulation (EU) 2018/1091 - see Table 3. The earliest reference periods were applied in Luxembourg (ending on 1 February 2023) and in Germany (ending on 28 February 2023).

In its 2023 quality report, Germany reported that, for the variables on 'other gainful activities', the reference period was the 2022 calendar year, in order to ensure comparability over time of these variables.

Rural development measures

Regarding the rural development measures specified in Annex IV to Regulation (EU) 2018/1091, all countries used the three-year period ending on 31 December 2023 as the reference period.

With the exceptions of Greece, Cyprus, Portugal and Romania, all countries used administrative sources to obtain the data required on rural development measures.

Comparability of the reference periods between 2020 and 2023

The following countries did not modify the reference periods between the 2020 and 2023 data collections: Bulgaria, Czechia, Germany, Estonia, Ireland, Greece, Spain, France, Croatia, Cyprus, Latvia, Lithuania, Malta, the Netherlands, Poland, Portugal, Romania, Slovakia, Finland and Norway.

Changes occurred in the following countries:

Belgium

In 2023, the 12-month irrigation reference period ended on 30 September. In 2020, it was on 15 October.

Denmark

Between 2020 and 2023, the reference periods for land, irrigation and labour force variables changed by a few days, as did the reference date for livestock other than cattle and for 'all other variables'.

Hungary

There was a very minor change for labour force variables: the reference date changed from 31 May in 2020 to 1 June in 2023.

Italy

The reference day for 'all other variables' changed from 1 December in 2020 to 31 October in 2023.

Luxembourg

There were changes between 2020 and 2023 for the following variables:

	IFS 2020	IFS 2023
Livestock variables	1 April 2020	1 February 2023
Labour force variables	The 12-month period ending on 1 April 2020	The 12-month period ending on 1 February 2023
All other variables for which no reference periods or reference days are specified in the quality report	1 April 2020	1 February 2023

Austria

The reference date for 'all other variables' – that is, all variables except those on land, irrigation, soil management practices, livestock, animal housing, manure management, labour force, and rural development measures - changed from 1 March in 2020 to 1 April in 2023.

Sweden

The reference date for livestock variables is the first Thursday in June every year. This means the weekday-based rule stays the same (the first Thursday), but the exact calendar date changes from year to year. For example, in 2020 the reference date was 4 June, while in 2023 it was 1 June.

Slovenia

In 2023, the reference day for livestock was 1 June. In 2020, it was 1 February. In 2023, the 12-month reference period for the labour force ended on 1 June. In 2020, it ended on 1 December. These differences in reference dates and periods may slightly affect the comparability of livestock and labour force data between 2020 and 2023.

Definitions of reference periods within the legislation - FSS 2010 and FSS 2013

The definitions of farm structure survey reference periods are provided in Article 8 of the Regulation (EC) No 1166/2008 as follows:

for land characteristics specified in Annex III of the same Regulation, a period of 12 months ending on a reference day between 1 March and 31 October of the survey year;
for livestock characteristics specified in Annex III, a reference day between 1 March and 31 December of the survey year;
for labour force characteristics specified in Annex III, a period of 12 months ending on a reference day between 1 March and 31 October of the survey year;
for rural development measures specified in Annex III, a period of three years ending on 31 December of the survey year.

Moreover, Article 16 of the same Regulation provides derogations for Greece, Spain and Portugal, where the references to the year 2010 are replaced by references to the year 2009.

FSS 2013: comparability of reference periods across countries and with respect to the legislation

Countries generally applied the reference periods and/or days within the limits set by Article 8 of Regulation (EC) No 1166/2008 . However, there is a broad diversity in the nationally applied reference periods, both in the level of detail as well as in the justifications provided, thus rendering the comparability between countries rather complex. Below, the analysis of the national reference periods in the FSS 2013 is provided according to the groups of characteristics covered.

Land characteristics

Concerning the reference period used for land characteristics (see Table 1), the earliest reference periods are used in Belgium (March 2013 for Wallonia and April 2013 for Flanders) and Luxembourg (from 2 April 2012 to 1 April 2013), whereas the latest reference period allowed by Regulation (EC) No 1166/2008 (from 1 November 2012 to 31 October 2013) was applied in France, Italy, Portugal, Slovakia and Sweden. Germany applied the 2013 calendar year so as to have the period for the land characteristics harmonised with the reference period of the Integrated Administration and Control System (IACS), which is used to take the values of the land characteristics. Iceland also applied the 2013 calendar year to ensure the comparability of the data with other data collected within Statistics Iceland, which are usually performed on a yearly basis.

While Regulation (EC) No 1166/2008 requires a period of 12 months for land characteristics, a few countries deviate from this requirement. More specifically, Belgium applied a single-month reference period, while Hungary and Norway used a single reference day. However, it is assumed that the land characteristics indirectly refer to a 12-month period, given their definitions, while the data are collected on the indicated day.

Livestock characteristics

Regarding livestock characteristics, all reporting countries used a reference day between 1 March and 31 December 2013 in compliance with Regulation (EC) No 1166/2008 with the exception of Portugal, which used the day of interview, i.e. a reference day between November 2013 and May 2014 (see Table 2). Portugal, however, indicated in the 2013 NMR that the deviation is minimal, because the likelihood of changes in the livestock number in the winter season is quite low. Nevertheless, this should be considered when comparing the FSS data with other countries. More generally, the diversity of the reference days used for livestock characteristics is clearly shown by the fact that the earliest reference day, already on 1 March 2013, was applied by Germany and the latest reference day of 31 December 2013 was used in Romania.

Labour force characteristics

As concerns labour force characteristics, all reporting countries used a reference period of 12 months ending on a reference day between 1 March and 31 October 2013 in compliance with Regulation (EC) No 1166/2008 (see Table 3). The earliest reference period was applied in Germany (ending in February 2013) and in Norway (ending on 1 March 2013).

Germany indicates in the NMR 2013 that the reference period for the labour force employed by agricultural holdings started in March 2012 and ended in February 2013, the duration of which actually falls one day short of the requirement set forth in the above Regulation. Nevertheless, such a difference may be considered negligible. The latest reference period, i.e. ending on 31 October 2013, was applied in six countries (France, Italy, Austria, Portugal, Slovakia and Iceland).

Rural development measures

Regarding the rural development measures specified in Annex III of Regulation (EC) No 1166/2008, a period of three years ending on 31 December 2013 should be applied in the FSS 2013. Only a few countries applied a slightly different reference period compared to the above Regulation, namely the Netherlands (a three year-period ending in March 2013) and Slovenia (a three year-period ending on 31 May 2013). It should be noted that these countries used administrative sources to obtain the requested data on rural development measures. Additionally, three other countries used a different period in 2013 than the one requested in the above Regulation. Cyprus, Hungary and Malta referred to the years 2010, 2011 and 2012. Hungary and Malta used administrative sources to obtain the requested data on rural development measures.

Comparability of the reference periods between 2010 and 2013

The following countries did not modify the reference periods between the 2010 (2009) and 2013 surveys: the Czech Republic, Germany, Estonia, Ireland, Greece, Spain, France, Croatia, Latvia, Lithuania, Hungary, Malta, the Netherlands, Austria, Portugal, Slovenia, Slovakia, Finland, the United Kingdom and Iceland. Changes occurred in the following countries:

Belgium

Compared to the reference periods/days used in the FSS 2013, the reference periods/days used in the 2010 census were slightly different. The reference period used for crop characteristics was a single reference day (1 May) in 2010 compared to March (for Wallonia) and April (for Flanders) in 2013, while for livestock characteristics the difference is only 15 days (1 May 2010 compared to 15 May 2013).

Bulgaria

In 2013, Bulgaria modified the reference period/day for livestock and labour force characteristics. As concerns livestock characteristics, the data referred in 2010 to 31 August, i.e. to a reference day two months earlier than the one used in 2013 (1 November 2013), while the reference period for labour force characteristics ended on 31 August 2010, i.e. it ended one month earlier than in 2013.

Denmark

In Denmark, practically no difference exists as the reference day of the 2013 survey was set to 13 May and in 2010 it was 14 May.

Italy

Compared to the reference day of 1 December 2013 applied to the livestock characteristics in the FSS 2013, in 2010 Italy used 24 October 2010 as the reference day for livestock.

Cyprus

The reference periods/days applied in 2010 were slightly different compared to those used in 2013. Concerning the land and labour force characteristics, the period from 1 October 2009 to 30 September 2010 was applied in the 2010 census, while for livestock characteristics the reference day was 1 November in 2010. This, however represents a difference of only one month compared to the FSS 2013, where for land use and labour force characteristics the period from 1 September 2012 to 31 August 2013 was used and for livestock the reference day used was 1 October 2013.

Luxembourg

Instead of the 12-month period ending on 15 May used in 2010, Luxembourg applied the reference period of 12 months ending a month and a half earlier, i.e. on 1 April for labour force characteristics in the FSS 2013.

Poland

With the exception of the rural development characteristics, for all other groups of characteristics, i.e. land, livestock and labour force, the reference days/periods applied in the FSS 2013 were set one month earlier than in the 2010 census.

Romania

The reference period applied for livestock characteristics was set one month earlier in 2010 compared to the FSS 2013, i.e. 1 December 2010 instead of 31 December 2013.

Sweden

There was a negligible difference of five days applied to the reference day for livestock characteristics, i.e. in 2010 the reference day was 10 June while in the 2013 survey it was 5 June.

Norway

The reference period applied in Norway to labour force characteristics began five months earlier in the FSS 2013 compared to the 2010 census. Instead of the 12-month period prior to 31 July 2010, the 12-month period prior to 1 March 2013 was used.

Conclusions

Small differences in national reference periods and reference days across countries may slightly affect the comparability of certain data, although the overall impact is difficult to quantify.

Changes in national reference periods and reference days between 2010 and 2013, as well as between 2020 and 2023, were generally minor and likely had little effect on the total number of holdings. However, for specific variables, particularly livestock, changes in the reference day may have affected comparability over time.

Source data for tables and graphs

Farm structure survey - reference periods: tables

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Thematic section

Publications

Integrated farm statistics manual, 2023 survey (Manuals and guidelines)
Integrated farm statistics manual – 2020 edition (Manuals and guidelines)
Key figures on the European food chain – 2025 edition (Key figures)
Principal quality characteristics of EU countries’ farm data collections for 2023 (Statistical reports)

Methodology

Farm structure (ESMS metadata file - ef_esms)
National methodological reports

Legislation

Summaries of EU Legislation: EU integrated farm statistics
Regulation (EU) 2018/1091 of the European Parliament and of the Council of 18 July 2018 on integrated farm statistics and repealing Regulations (EC) No 1166/2008 and (EU) No 1337/2011
Commission Implementing Regulation (EU) 2024/2914 of 25 November 2024 on the data to be provided for the reference year 2026 pursuant to Regulation (EU) 2018/1091 of the European Parliament and of the Council on integrated farm statistics as regards the list of variables and their description
Commission Implementing Regulation (EU) 2021/2286 of 16 December 2021 on the data to be provided for the reference year 2023 pursuant to Regulation (EU) 2018/1091 of the European Parliament and of the Council on integrated farm statistics as regards the list of variables and their description and repealing Commission Regulation (EC) No 1200/2009
Commission Implementing Regulation (EU) 2018/1874 of 29 November 2018 on the data to be provided for 2020 under Regulation (EU) 2018/1091 of the European Parliament and of the Council on integrated farm statistics and repealing Regulations (EC) No 1166/2008 and (EU) No 1337/2011, as regards the list of variables and their description
Commission Regulation (EC) No 1200/2009 of 30 November 2009 implementing Regulation (EC) No 1166/2008 of the European Parliament and of the Council on farm structure surveys and the survey on agricultural production methods, as regards livestock unit coefficients and definitions of the characteristics
Regulation (EC) No 1166/2008 of the European Parliament and of the Council of 19 November 2008 on farm structure surveys and the survey on agricultural production methods and repealing Council Regulation (EEC) No 571/88
Council Regulation (EEC) No 571/88 of 29 February 1988 on the organisation of Community surveys on the structure of agricultural holdings between 1988 and 1997

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