Informative Inventory Report Slovenia 2018

2018 INFORMATIVE INVENTORY REPORT for SLOVENIA

190

Emissions from animal housing manure stores and due to fertilization with animal manures in cattle production Emission factors which tell us how much of N from animal excreta is lost to the atmosphere in the form of ammonia depend on manure management systems Factors along with some basic information on manure management systems in cattle production are presented in Table 517 Generally EMEPEEA factors were used In case of introduction of abatement techniques the basic emission factors were multiplied by (1- efficiency coefficient) Efficiency coefficients were obtained either from EMEPEEA manual or from Draft revised United Nations Economic Commission for Europe Framework Code for Good Agricultural Practice for Reducing Ammonia Emissions (ECEEB AIR20148) The fraction of individual manure management systems was estimated on the basis of the results of farm census data from 1991 and 2000 Since manure management systems were not reported in the census data on size and structure of cattle-breeding farms were used for rough estimates It was considered that all farms with less than 10 head of bovine animals had solid manure storage systems that 30 of farms with 10-19 head of animals practiced liquid manure storage and 70 of them solid manure storage and that all farms with 20 cows or more had liquid manure storage systems Linear regression was used to estimate the changes in manure management systems in the period 1990-2000 After 2000 data on farm size and structure were reported by the Statistical Office for the years 2003 2005 2007 2010 2013 and 2016 For the years with missing values the proportions of various manure storage systems were obtained by interpolation or extrapolation Animals kept in liquid systems were further divided into animals kept in liquid manure storage with natural crust cover animals kept in liquid manure storage below animal confinements and animals from which the excreta was treated in anaerobic digesters Based on information on manure management that was collected in the frame of milk recording service on a large number of dairy farms in 2005 (Babnik and Verbič 2007) it was estimated that the ratio between slurry stored in stores with natural crust and slurry stored below animal confinements is 046054 Based on information from the same source the solid manure was divided into farmyard manure stored in heaps and deep bedding (090010) The proportion of slurry treated in anaerobic digesters was estimated on the basis of data collected from biogas plants by the means of interview (data provided by Poje unpublished) Based on above mentioned data and data on total number of cattle it was estimated that during the period 2006-2010 the proportion of digested cattle manures increased from 003 to 036 Anaerobic digesters were not markedly spread thereafter and therefore the same value was used for the period 2011-2016 The fraction of grazing bovine animals for 1990 has been estimated on the basis of data on grazing animals on mountain pastures and expert estimate on the scale of grazing on intensive grasslands (Verbič et al 1999) In 2000 all grazing animals on mountain and other pastures were recorded This census showed that in 2000 one way or another 21 of animals were grazing This data have been corrected with regard to the length of the grazing season considering the fact that animals on mountain pastures will graze for 141 days on the average and on other pastures for 210 days As result the corrected proportion of grazed animals for 2000 was estimated to be 0117 The same procedure was used for the data obtained by sample survey on agricultural production methods in 2010 It showed that the corrected proportion of grazed animals increased to 0126 The estimate for 1990 was used for the period 1985-1990 For the period 1991-1999 the data on grazing were obtained by linear regression which was calculated on the basis of data for the years 1990 and 2000 and for the period 2001-2009 the estimates obtained by linear regression for the years 2000 and 2010 For the years thereafter extrapolated values based on 2000-2010 period were used It has been estimated that the fraction of grazing animals and the fraction of liquid manure management systems have increased while the fraction of bovine animals in straw based systems has decreased Detailed information on grazing and distribution of manure management systems is given in Table 516