ANNUAL QUALITY REPORT

Transcription

1 ANNUAL QUALITY REPORT FOR THE SURVEY ON THE CONSUMPTION OF MINERAL FERTILISERS ON FAMILY FARMS BY AGRICULTURAL CROPS (KME-PMD/DK) FOR 2014 Prepared by: Enisa Lojović Hadžihasanović and Jerneja Pikelj Date: February /13

2 Table of Contents 0 Methodological Explanations Relevance Rate of Unavailable Statistics Accuracy Sampling Errors Sampling Error Coverage Bias Coverage Bias Non-Sampling Errors Non-Response Errors Unit Non-Response Rate Item Non-Response Rate Imputation Rate Coverage Errors Overcoverage Rate Measurement Errors Editing Rate Rate of the Coherence of Data Sources Timeliness and Punctuality Timeliness Timeliness of the First Results Timeliness of Final Results Punctuality Punctuality of the First Results Accessibility and Clarity Accessibility Means Used for the Dissemination Clarity Results Presented Level (Detail) of Presentation Comparability Comparability over Time Length of Comparable Time Series Breaks in Time Series Geographical Comparability Comparability with Other Members of the European Statistical System Seasonal Adjustment Coherence Coherence between Provisional and Final Data Coherence between Provisional and Final Data Coherence with the Results of the Reference Survey Reference Survey Coherence with Reference Data Costs and Burdens Survey Costs of the Office Burden of Reporting Units /13

3 0 Methodological Explanations Brief Description of the Survey The purpose of the survey is to estimate the mineral fertiliser consumption in the production of particular crops and on this basis to estimate the consumption of mineral fertilisers by main categories of utilised agricultural areas (UAA) and by total utilised agricultural areas in Slovenia in the reference period. Additionally we estimate the mineral fertiliser consumption by main categories of utilised agricultural areas in cohesion regions. Legal Basis for the Survey The legal basis for this survey are the National Statistics Act (OJ RS, No. 45/95 and 9/2001 changes and amendments) and the Annual Programme of Statistical Surveys for the reference year, published in the Official Journal. There are also the Communication from the Commission to the Council and to the European parliament (COM/2006/0508); on the calculation of agriculture and environmental indicators at the EU level), and Regulation amending the Regulation on the protection of waters against pollution caused by nitrates from agricultural sources (OJ RS, No. 5/2013), which represents the indirect legal basis for this survey. Observation Units Observation units are agricultural holdings with crop production, satisfying the criteria of an EU-comparable threshold (European size class farms). Coverage The survey is carried out as a module or a subsample of the sample survey on crop production entitled Areas sown KME-JUN and with it we collect the data from selected agricultural holdings engaged in crop production in the reference period in Slovenia. It means that the sampling frame of the KME-PMG/DK survey covers all agricultural holdings from the statistical survey Areas sown KME-JUN (their crop production and permanent grassland production) and all active agricultural holdings from the Statistical register of agricultural holdings with agricultural production of grapes, fruit and olive. The sample design is stratified simple random sampling. In 2014 the sampling frame contained about 60,000 agricultural holdings. 11,978 sampling units were selected in the sample. Data from family farms were collected in the CATI mode and data from agricultural enterprises were gathered by post during the implementation of the annual statistical survey KME-PMG. The KME-PMG/DK survey is implemented every second year. Key Variables The key variables of this survey are: the utilized agricultural areas and the quantities of used mineral fertilisers. Key Statistics 3/13

4 The key statistics of this survey are: fertilized utilized agricultural areas by defined, selected agricultural crops and main land use categories, and the quantities of used main plant nutrients (nitrogen, phosphorus and potassium). Questionnaire The questionnaire is available only in Slovene on the website: Methodological Explanations The methodological explanations are available on the website: 4/13

5 1 Relevance 1.1 Rate of Unavailable Statistics In 2014 we implemented the statistical survey KME-PMG/DK to estimate the fertilised agricultural areas and the quantities of used plant macro nutrients at the level of Slovenia and also at the level of the cohesion regions. In this way we met the needs of the major part of data users, among others also those of Eurostat. As there is no legal act to determine the obligatory statistics at the EU level we could say that the rate of unavailable statistics is 0%. 2 Accuracy 2.1 Sampling Errors Sampling Error The coefficient of variation (CV in %) was calculated for the estimation of the fertilized crop areas (some predefined agricultural crops) and main land cover categories and for the estimation of the used quantities of main plant nutrients in kilograms. This calculation was made by SAS software. We publish the CV calculations for fertilized crop areas and the use of Nitrogen (N) as macro plant nutrient. If the coefficient of variation for the particular estimation was 15% or less (CV <= 15%), the estimate was of acceptable precision and was published without limitations. If the coefficient of variation for the particular estimation was over 15% including 30% (15% < CV <= 30%), the estimate was less precise and was flagged with caution with the letter M. 5/13

6 Table 2.1: Accuracy of estimated fertilised UAA, total and by cohesion regions Categories of UAA Slovenia Cohesion region Vzhodna Slovenija Cohesion region Zahodna Slovenija coefficient of variation (%) UAA Arable land Cereals for grains wheat barley maize for grains buckwheat Dried pulses Root crops potatoes fodder root crops Industrial plants oil turnip rape pumpkins for oil hops Vegetables Green fodder silage maize green fodder from arable land Other crops Permanent grassland one harvest two harvests three harvests more than three harvests Permanent crops Fruit and olive in plantations and nurseries Extensive orchards Vineyards Stubble crops no occurrence of event When calculating the coefficients of variation (CV) for the utilised agricultural areas we considered only those areas where the sum of used plant macronutrients N, P 2 O 5, K 2 O > 0. Therefore the values of the CV in agricultural crops with smaller number of sown areas and especially with those that are usually only rarely fertilised with mineral fertilisers are a little higher than the CV in other crops. For instance: industrial plants are considered to be sown mainly in Vzhodna Slovenija (in Zahodna Slovenija there are few agricultural holdings with these crops), for permanent grassland and pasture used once, extensive orchards and subsequent crops it is characteristic that they are more rarely fertilised with mineral fertilisers than other crops. 6/13

7 Due to changes made when calculating the CV for the fertilised areas of agricultural land for 2014, these calculations of the CV are not comparable to those from previous years. In the 2014 calculations only those areas we considered, where the condition applied that the sum of all used plant macronutrients N, P 2 O 5, K 2 O > 0. Table 2.2: Accuracy of the estimated consumption of the plant nutrient N, total and by cohesion regions Categories of UAA Slovenia Cohesion region Vzhodna Slovenija Cohesion region Zahodna Slovenija coefficient of variation (%) UAA Arable land Cereals for grains wheat barley maize for grains buckwheat Dried pulses Root crops potatoes fodder root crops Industrial plants oil turnip rape pumpkins for oil hops Vegetables Green fodder silage maize green fodder from arable land Other crops Permanent grassland one harvest two harvests three harvests more than three harvests Permanent crops Fruit and olive in plantations and nurseries Extensive orchards Vineyards Stubble crops no occurrence of event When calculating the CV for use of plant nutrient N we considered only the data of those crop products where the sum of all used plant macronutrients N, P 2 O 5, K 2 O > 0. 7/13

8 2.2 Coverage Bias Coverage Bias Due to the non-response of some agricultural holdings obtained data were weighted and in this way the underestimation is prevented. Real bias of the estimations cannot be calculated. 2.3 Non-Sampling Errors Non-Response Errors Unit Non-Response Rate Table 2.3: Unit non-response rate Reference period Number of adequate units 11,065 11,084 12,000 11,978 Number of non-responses 3,540 2,377 2,594 3,285 Non-response rate (%) Item Non-Response Rate In this survey, except for the indicator unit non-response rate, all the other quality indicators are calculated in such a way that the use of plant macronutrients are grossed up on the level of the agricultural crops (the calculations for 2012 were made on the level of agricultural holdings as observed units). In case of fertilized areas we reasonably considered either that all the areas > 0 or the areas with the sum of used plant macronutrients N, P 2 O 5, K 2 O > 0. Thus we calculated that on national level the item non-response rate for the fertilised area in raw data accounted for 0%, the item non-response rate for use of N/kg was 0.8%, the item non-response rate for use of P 2 O 5 /kg was 19.8% and the item nonresponse rate for use of K 2 O/kg was 19.8%. In this case the fertilised areas were considered to comprise the areas with the sum of used macronutrients N, P 2 O 5, K 2 O > 0. As in the calculation, the statement of the farmer who did not use the mineral fertilisers with P 2 O 5 or K 2 O plant nutrient, is not a missing value, but the value for the use is 0, these calculations can be interpreted in such a way as to say: out of all agricultural cultures that were fertilized with mineral fertilisers about 20% were fertilized only with fertilisers that comprised the plant nutrient N. The stated non-response rate in case of individual variables remained almost the same also upon weighting. If calculations of the item non-response rate had considered all the crops on agricultural holdings with agricultural areas > 0 as the single criterion for making calculations (without the additional criterion that the sum of used plant macronutrients N, P 2 O 5, K 2 O > 0), the item non-response rate for fertilised areas would have been about 25% of all agricultural areas in the sample. Having weighted these data and having taken into account the areas pertaining to ecologic farming, i.e. areas not fertilised with mineral fertilisers, the share of areas that were not fertilised would have been estimated at 42% of all the agricultural areas in /13

9 Imputation Rate Table 2.4: Rate of imputed data, Slovenia, 2014 Imputation rate % Weighted imputation rate % Fertilised agricultural areas Use of plant nutrient N Use of plant nutrient P 2 O Use of plant nutrient K 2 O The imputation rate is calculated as the percentage of the number of all agricultural crops on all agricultural holdings in the sample, for which imputation of data was made. The weighted imputation rate is the percentage of weighted imputed data for the observed variables stated in the lines in the table. Table 2.5: Rate of imputed data by cohesion regions, 2014 Vzhodna Slovenija Zahodna Slovenija imputation rate % weighted imputation rate (%) imputation rate % weighted imputation rate (%) Fertilised agricultural areas Use of plant nutrient N Use of plant nutrient P 2 O Use of plant nutrient K 2 O The tables given above indicate that the percentages of the imputed, weighted data are fairly larger than the shares of imputed data that were not weighted. This is the result of the imputation of data to data of agricultural holdings with larger areas of agricultural crops. Except in case of ecologic farming or market-oriented production of berries, seeds and plants and flowers and ornamental plants, we believe that the probability of use of mineral fertilisers is larger on larger agricultural holdings than in case of smaller ones. Namely, these small agricultural holdings often grow crops only for their own use and the quantity of crops is not the first priority. The differences among both cohesion regions in Slovenia arose also due to the item non-response rate Coverage Errors Overcoverage Rate There are no inadequate units, as the sample contained only the units for which it was certain that they had crop production in the reference year (statistical surveys and administrative data). 9/13

10 2.3.3 Measurement Errors Editing Rate Table 2.6: Editing Rate, Slovenia, 2014 Editing rate % Weighted editing rate (%) Fertilised agricultural areas Use of plant nutrient N Use of plant nutrient P 2 O Use of plant nutrient K 2 O The editing rate is calculated as the percentage of number of all agricultural crops on all agricultural holdings covered in the sample, the data of which were edited. The weighted editing rate is the percentage of weighted edited data for the variables stated in the lines in the table. Table 2.7: Editing Rate by cohesion regions, 2014 Vzhodna Slovenija editing weighted rate editing % rate (%) Zahodna Slovenija editing weighted rate editing % rate (%) Fertilised agricultural areas Use of plant nutrient N Use of plant nutrient P 2 O Use of plant nutrient K 2 O Rate of the Coherence of Data Sources The rate of coherence of data sources cannot be calculated as the units and the variables observed in this survey differ from those in the reference survey. Comparability between both surveys is viable only in view of the calculated statistical data. 3 Timeliness and Punctuality 3.1 Timeliness Timeliness of the First Results Table 3.1: Timeliness of the First Results Reference period 2014 Date of publishing Time lag (months) T Timeliness of Final Results Data published in the First Release are also final results. Timeliness of final results is therefore the same as timeliness of the first release. 10/13

11 3.2 Punctuality Punctuality of the First Results Table 3.2: Punctuality of the First Results Reference period 2014 Announced date Publishing date Difference (days) 0 4 Accessibility and Clarity 4.1 Accessibility Means Used for the Dissemination Table 4.1: Means Used for Dissemination No.: Mean Used Website 1 (e.g. First Release, E-release) YES 2 Publication in the SI-STAT Data Portal YES Publication in the interactive web tools (e.g. Interactive Statistical Atlas of Slovenia, 3 Thematic Cartography) NO Ad hoc prepared data for users according to their 4 specification YES 5 Data available through telephone answering machine NO General printed publications 6 (e.g. Stat o book) NO Thematic printed publications 7 (e.g. Rapid Reports, Brochures) NO External databases (e.g. Social Science Data Archives, Eurostat, OECD 8 databases) YES 9 Statistically protected micro data NO Preliminary access to data according to standard 10 protocol NO 4.2 Clarity Results Presented The survey results are presented as absolute figures, indices, and graphs Level (Detail) of Presentation The estimation on the particular agricultural crops and the used mineral fertilisers are presented at national level (NUTS 0 level) while the estimation on used mineral 11/13

12 fertilized by main land cover categories are presented at cohesion regions (NUTS 2 level). 5 Comparability 5.1 Comparability over Time Length of Comparable Time Series Data on the consumption of mineral fertilisers at family farms by agricultural crops are available from 2006 on Breaks in Time Series Due to conduct of the 2010 Agricultural Census, the statistical survey on the consumption of mineral fertilisers by crops was not carried out. These data were estimated with a different methodology. 5.2 Geographical Comparability Comparability with Other Members of the European Statistical System At Eurostat preparations are under way on the methodology that should ensure improved comparability among EU Member States. 5.3 Seasonal Adjustment Seasonal adjustment is not applied in these surveys. 6 Coherence 6.1 Coherence between Provisional and Final Data Coherence between Provisional and Final Data Provisional data are not published. We publish final data. 6.2 Coherence with the Results of the Reference Survey Reference Survey The reference survey is an annual statistical survey entitled Use of mineral fertilisers. With it the volume of used mineral fertilisers and plant nutrients in mineral fertilisers is estimated. Yet, it can neither be used to estimate the areas of fertilized areas nor to estimate the use of mineral fertilisers or plant macronutrients on the level of cohesion regions Coherence with Reference Data Table 6.1: Compliance with the results of the annual survey on use of mineral fertilisers 12/13

13 Reference period 2014 Differences in the estimation of the used plant macro nutrients regarding the reference survey (%): Nitrogen plant nutrient (N) Phosphorus plant nutrient (P 2 O 5 ) Potassium plant nutrient (K 2 O) We believe that slightly larger differences in the estimates on use of the Nitrogen plant nutrient mainly result from the differences between both survey methodologies. Apart from that, the slightly lower estimate on use of the Nitrogen plant nutrient was influenced by the estimated basic areas of permanent grassland by categories of the intensity of use. When estimating the basic areas in 2004, which was a year with lots of rain, we kept the ratios among the categories of use of permanent grassland that were acquired in 2013, which was a year with little rain. This reflected both in the estimates of the fertilised areas of permanent grassland, by categories of use, and also in the total quantities of used Nitrogen plant nutrient. The decrease of areas fertilised with mineral fertilisers and use of plant micronutrients was the result also of the increase in the number of agricultural holdings with ecologic farming and the increase in the areas which they did not fertilise with mineral fertilisers. 7 Costs and Burdens 7.1 Survey Costs of the Office Table 7.1: Survey costs at the Statistical Office Reference period 2014 Number of working hours spent 3,758 Number of reporting units that had to fill in 11,978 questionnaires Survey period biannual Number of questionnaires biannualy (total) Burden of Reporting Units Table 7.2: Burden of the reporting units Reference period 2014 Number of reporting units that submitted the data 8,693 1 Annual number of questionnaires per unit Time spent to fill in a questionnaire (hours) 0.3 Total time spent (hours) 2,608 13/13