THE SAMPLING APPROACH IN SLOVENIA 2nd Joint Workshop on Pesticide Indicators, Istanbul (Turkey), September 13 – 14, 2007 Katja Rutar, Enisa Lojović Hadžihasanović, Simona Dernulc Statistical Office of the Republic of Slovenia

SAMPLING IN AGRICULTURE SLOVENIA Stratification is based on the data of different agricultural products due to mixed type of agricultural production At least 1 species of animals is bred at 87% of agricultural holdings Arable land is cultivated by 93% of agricultural holdings Type of farming according to FSS 2005 49 % of farms have mixed type of farming 35 % of farms are specialized in livestock rearing and milk production 16 % of farms are spcialized in arable and permanent crop production

CRITERIA FOR STRATIFICATION Stratum1 Stratum2 Stratum3 Stratum4 UAA (are) 2000 or more 800-<2000 500 - <800   <500 Arable land and wheat (are) >= 600 and >= 250 300 - < 600 and 100 – < 250 100 - < 300 and 50 - < 100 < 100 and < 50  Extensive orchards (No of trees) >= 150 100 - < 150 50 - < 100 < 50  Vineyards (are) >= 500 300 - < 500 100 - < 300  < 100  Orchards plantations (are) >= 200 100 - < 200 < 50 Potatoes (are) >= 100 25 - < 50 < 25 Hops (are) <100  Sugar beet (are) Cattle, total (No) >= 40 15 – 39 5 - 14  1 – 4 Pigs, total (No) 20 – 39 4 - 19  1 – 3 Sheep and goats, breeding animals (No) >= 30 20 – 29 10 – 19 1 – 9 Broilers (No) >= 1000 100 – 999 50 – 99 1 – 49 Laying hens (No) 100 - 999 Other poultry (No) Horses (No) >= 20 5 – 9 Deer (No) Quail (No) 10 - 19 Rabbits (No) >= 75 50 – 74 25 - 49 1 – 24 Ostriches (No) 5 - 9 Behives (No) >= 50 2 0 - 49

NUMBER OF FARMS IN THE SAMPLIG FARME AND SAMPLE BY STRATA, FSS 2005 Sampling frame Sample number share (%) Stratum 1 7003 7,8 % 41,2 % Stratum 2 19337 21,6 % 2339 13,8 % Stratum 3 30481 34,0 % 3686 21,7 % Stratum 4 32838 36,6 % 3972 23,4 % Total 89659 100,0 % 17000

WHEAT Share of farms growing wheat Share of area of wheat Stratum1 12% 40 % Stratum2 27% 30% Stratum3 41% 25% Stratum4 20% 6%

Coefficient of Variation ACCURACY OF DATA, FSS 2005 Coefficient of Variation Area of wheat 0.9% Area of cereals 0.7% Arable land, total Utilized arable area, total 0.8%

SAMPLE FRAME and SIZE for the PESTICIDE INDICATORS SURVEY In the FSS sample we have around 5300 farms cultivating wheat, representing around 21000 farms cultivating wheat in the country On the basis of FSS 2007 data for (only) area of arable land and wheat production four new stratum were defined From that frame we selected a stratified random sample (4 stratum * 12 NUTS3 regions) of 2900 farms cultivating wheat All enterprises cultivating wheat will be included in the sample (around 100)

DATA COLLECTION METHODS for the PESTICIDE INDICATORS SURVEY One of (national) aims of the Pesticide indicators survey is to test appropriatenes of different modes of data collection for the survey about pesticide use On the basis of available resources we will devide the sample of 2900 farms in: Paper assisted personal interviewing (PAPI) ~ stratified sample of around 200 farms Postal surveys (POST) ~ stratified sample of around 1350 farms Computer assisted telefon interviewing (CATI) ~ stratified sample of around1350 farms

IDEAL ACCURACY OF DATA for WHEAT PRODUCTION Total wheat production in ha : CV ~ 2,3% Wheat production in ha in: Stratum1 : n ~ 1300 ; CV ~ 4,6% Stratum2 : n ~ 750 ; CV ~ 5,3% Stratum3 : n ~ 530 ; CV ~ 5,5% Stratum4 : n ~ 320 ; CV ~ 6,6% Face-to-face data collection : n ~ 200 ; CV ~ 10,1% CATI data collection : n ~ 1350 ; CV ~ 4,4% POST data collection : n ~ 1350 ; CV ~ 3,5%