State Plant Health and Seed Inspection Service Plant Protection Institute, Sośnicowice Branch Central Statistical Office of Poland PILOT PROJECT: Transition Facility Multi-Beneficiary Statistical Co-operation Programme 2005 Lot 2: Pesticide indicators ESTIMATION OF NATIONAL RESULTS IN PILOT PROJECT „PESTICIDE INDICATORS” – POLAND Authors: Central Statistical Office of Poland – Grazyna Berent-Kowalska – Bronislaw Lednicki State Plant Health and Seed Inspection Service – Katarzyna Prugar Plant Protection Institute Sosnicowice Branch – Wojciech Sliwinski – Stanislaw Stobiecki

PRESENTATION OUTLINE Review the way of performing the project in Poland Computing the average pesticide use indicator The results for the average pesticide use indicator for three voivodships Presentation of methods for generalizing the results to the entire country (2 methods) Average usage indicator – estimate for the entire country Average usage indicator – based on 2003-2007 projects Examples of results following the estimation for the entire country Survey quality Summary Recommendations for the national – scale monitoring

POPULATION FOR SURVEY STUDIES The surveyed population includes farms from the following provinces which have arable land areas over 1 ha and grow winter wheat study based on wheat harvested in 2006 lubelskie lodzkie zachodniopomorskie zachodnio pomorskie lodzkie lubelskie

THREE REGIONS SURVEYED For the purpose of the studies, three regions were selected, whose plant protection practices vary due to: Different geographic, climatic, soil conditions – different levels of infestation with diseases, pests and weeds. Different farm structure.

FARMS GROWING WINTER WHEAT IN SELECTED PROVINCES (2006) lubelskie lodzkie zachodnio- -pomorskie Number of farms 97 132 30 761 8 609 Winter wheat crop area (ha) 218 442 57 597 130 666

WINTER WHEAT CROP – CROP AREA

SAMPLE SELECTION SCHEME Optimal strata selection scheme was applied. Each province was divided into 5 strata. The division of the population into strata and the sample allocation among the strata was performed while applying the numeric optimization method. Optimization criterion – minimization of the coefficient of variance for total sown area.

STRATA LIMITS

NUMBER OF FARMS WITHIN THE POPULATION AND WITHIN SAMPLE ACCORDING TO STRATA Province strata h=1 h=2 h=3 h=4 h=5 total Lubelskie Nh nh 58788 28243 9036 1022 43 97132 38 32 30 27 170 Lodzkie 17553 8483 4041 634 50 30761 37 22 31 Zachodnio- -pomorskie Nh 6185 1758 481 130 55 8609 29 25

DEVELOPING A NEW SYSTEM OF DATA COLLECTION Internet-based system www.pesticide-indicator.pl Printing questionnaires with sampled farms data. Entering data into the electronic survey format by inspector. Feeding the survey data into the database over the internet. Establishing communication between the inspectors and coordinators and the data administrator and project manager. Internal Control.

AVERAGE PESTICIDE USAGE INDICATOR (R) X – pesticides use (AS) in kg Y – crop area Sample selection for the pilot project: Voivodship – index „w” (w = 1, 2, 3) Stratum – index „h” (h = 1, 2 ... 5) Farm – index „i” (i = 1, 2, ..., nwh) nwh – number of farms selected to the primary sample from the h-stratum of the w- voivodship

AVERAGE PESTICIDE USAGE INDICATOR (R) cont’d. (2) Consistent with the sampling scheme, the estimator of parameter R is: ( i = 1, 2, … , nwh; h = 1, 2, … , 5; w = 1, 2, 3) where: xwhi – pesticide usage (AS) at the i-farm sampled from the h-stratum of the w- voivodship, ywhi – winter wheat crop area at the i-farm within the h-stratum of the w- voivodship, wwhi – weight assigned during sampling to the i- farm within the h- stratum of the w- voivodship

AVERAGE PESTICIDE USAGE INDICATOR (R) cont’d. (3) Computing the weight: ( i = 1, 2, … , nwh) gdzie: Nwh – number of farms within the h-stratum of the w-voivodship,  nwh – number of farms randomly drawn for the (primary) sample from the h-stratum of the w- voivodship We use adjusted weight because of the necessity of drawing from the reserve sample due to refusal of participation in the survey or other reasons.

THE ADJUSTED WEIGHT The study realization is not ideal in reality. in cases when a farm cannot be surveyed due to refusal to participate in study or similar causes the primary sample needs to be altered to include a farm from the reserve list Primary weight wwhi is adjusted using the following multiplier mwhi : where:  nrwh – number of farms included in the study of the h-stratum of the w- voivodship from the reserve sample, nzwh – number of farms surveyed (from the primary sample and the reserve sample) within the h-stratum of the w- voivodship, nbwh – number of farms not surveyed (from the primary sample and the reserve sample) due to refusals or similar reasons

THE ADJUSTED WEIGHT (cont.’d) The adjusted weight wkwhi for the i-farm surveyed within the h-stratum of the w-voivodship will be as follows:

AVERAGE PESTICIDE USE INDICATOR CALCULATED FOR 3 VOIVODSHIPS lubelskie – 1.16 kg AS/ha lodzkie – 1.32 kg AS/ha zachodniopomorskie – 2.80 kg AS/ha the average value of the pesticide use indicator for the three voivodships 1.69kg AS/ha

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY Method I The voivodships in Poland would be divided into three groups, according to their farm structure (crop area allocated to winter wheat). Each group would contain one of the three voivodships included in the pilot project (lubelskie, lodzkie, zachodniopomorskie). For each of the three voivodships, we would compute the estimator rg which would denote pesticide usage in kg/ha.

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d) Method I (cont.’d.) We compute indicator for Poland according to the following formula (g = 1, 2, 3) g – voivodship group index where: Pg – winter wheat crop area in g-group of voivodships P – winter wheat crop area in Poland

Division of voivodships into three groups AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d) Method I (cont.’d.) Division of voivodships into three groups zachodnio pomorskie lodzkie lubelskie

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d) Method II Combine the results from the three voivodships Divide all surveyed farms into five farm size groups: less than 2 ha 2-5 ha 5-20 ha 20-150 ha over 150 ha Criteria for dividing the voivodship in such a way as to even the number of surveys in each size group.

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d) Method II (cont.’d) Estimator rg denoting the use of pesticides in kg/ha is calculated for each farm size group (g in this case is the number of the farm size group) Then we calculate the usage indicator for Poland (g = 1, 2, 3, 4, 5) – farm size group index where: Pg – winter wheat crop area in g-farm size group P – winter wheat crop area in Poland

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY – RESULTS According to Method I Pg1 = 662 505 ha Pg2 = 611 510 ha Pg3 = 479 386 ha P = 1 753 401 – winter wheat crop area in Poland winter wheat crop area in groups of voivodships rPOLAND = 1.84 kg/ha NOTE: When voivodships were grouped differently, the result was 1.93 kg/ha

AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY – RESULTS According to Method II Farm size group less than 2 ha 2-5 ha 5-20 ha 20-150 ha over 150 ha crop area in group Pg 323 981 337 812 435 201 354 712 301 692 average pesticide use in group rg 0.98 1.29 1.58 2.26 3.07 rPOLAND = 1.81 kg/ha NOTE: When divided into different farm size groups, the result was 1.80

AVERAGE PESTICIDE USE INDICATOR 2003 – 2007 STUDY RESULTS TYPE OF STUDY 2003 national monitoring by the Plant Protection and Seed Inspection Service (2700 farms) 2005: 2002 PHARE project (1 voivodship – 100 farms) 2007 Pesticide Indicator project – data from three voivodships 2007 Pesticide Indicator project – generalizing to the entire country according to Method I 2007 Pesticide Indicator project – generalizing to the entire country according to Method II AVERAGE PESTICIDE USE INDICATOR (kg of AS/ha) 1.85 2.14 1.69 1.84 1.81

EXAMPLES OF RESULTS AFTER ALL-COUNTRY GENERALIZATION AVERAGE USE OF ACTIVE SUBSTANCES PER CHEMICAL GROUP FUNGICIDES (example: top portion of table) Eurostat Code Product type Chemical group Average use (kg/ha) % of share in total use indicator (data from three voivodships) F1.2 Inorganic fungicides Inorganic sulphur 0.172 9.36% 0.141 F2.3 Fungicides based on carbamates and dithiocarbamates Dithiocarbamate fungicides 0.118 6.39% 0.125 F3.1 Fungicides based on benzimidazoles Benzimidazole fungicides 7.67% 0.148 F4.1 Fungicides based on imidazoles and triazoles Conazole fungicides 0.080 4.32% 0.075 F4.2 Imidazole fungicides 0.024 1.31% 0.023 F5.1 Fungicides based on morpholines Morpholine fungicides 0.055 3.01% 0.049

EXAMPLES OF RESULTS AFTER ALL-COUNTRY GENERALIZATION AVERAGE USE OF PESTICIDES PER TYPE 1.84 kg AS/ha

RATIO OF AREA TREATED WITH SELECTED ACTIVE SUBSTANCE TO TOTAL AREA TREATED (active substance area treated) EXAMPLES – top listings from selected types Eurostat Code Product Type AS Name Ratio [%] H6.3 herbicides isoproturon 5.01 F3.1 fungicides carbendazim 12.01 I1.1 insecticides alpha-cypermethrin 1.41

RATIO OF AREA TREATED WITH PRODUCT TYPES TO TOTAL AREA TREATED (active substance area treated) Product type Ratio [%] Fungicides 56 Herbicides 34 Insecticides 3 Other 1 Plant growth regulators 6 Total area treated with active substances: 13015674 ha

QUALITY OF PESTICIDE USE SURVEY Basic parameters: Quality of sample selection (sampling quality) – error analysis. Completeness of survey (evaluated as good – out of 569 sampled farms, there are 29 farms not surveyed, including the reserve sample). Technical accuracy (selection of the interviewers, data quality, data processing, calculations).

ERROR ANALYSIS – RESULTS Voivodship Average pesticide use indicator for voivodship (kg of AS/ha] Absolute standard error Relative standard error [%] lubelskie 1.1616 0.0733 6.31 lodzkie 1.3223 0.0905 6.84 zachodniopomorskie 2.8011 0.1201 4.29 TOTAL 1.6859 0.0584 3.47 NOTE: relative standard error is lower in the zachodniopomorskie voivodship due to a high number of large-size farms within the sample and less variety in the pesticides used

SUMMARY Average pesticide use indicator was calculated for winter wheat in three surveyed voivodships, using adjusted weight. Two methods of generalizing the results for the entire country were applied. Good consistency of the generalized results was observed with the 2003 national monitoring data. Sampling error was determined. The computed sampling error is low, considering the ratio of the number of farms to the number of farms growing winter wheat. Survey quality was evaluated as good. The right sample selection is the key element determining the outcome of the survey.

RECOMMENDATIONS FOR THE NATIONAL – SCALE MONITORING optimal, stratified sampling should be used important: sample size number of strata establishing the strata limits sampling should be performed from the entire population (total number of farms) it is necessary to define indicatores describing investigated parameters for national use the system of data collection should be automated data preparation and computing results from the usage studies should be automated