Danish rules and key values related to fertiliser and animal manure in general and requirements related to extension of the animal production, updated to year 2017/2018. Supplemental literature for the Agro-ecosystems master course: Agro-ecosystem analysis and management at Farm Scale (2016), see (Kristensen 2016) Dr. Ib Sillebak Kristensen, Dept. of Agroecology, Aarhus University. The written material about fertilisation rules and general requirements that have to be followed by the farmers are in Danish, and is published by the Plant Directorate in Vejledning om gødsknings- og harmoniregler (NaturErhvervstyrelsen 2016). An English summary of important parts is given her. Contents 1.1. Plant cover and catch crops... 1 1.2 N quota / N norms... 3 1.3. Utilisation of animal manure... 4 1.4. Storage and spreading time.... 5 2. Rules related to extension of the animal production... 9 2.1 Ammonia volatilization... 9 2.2. Instruments (Virkemidler) for reducing ammonia emission... 10 2.3 Phosphorus application... 11 2.4. Instruments (Virkemidler) for reducing phosphorus leaching/runoff... 11 2.5. Nitrate leaching surface water... 12 3. Litteratur.... 14 1. General rules for agriculture Ib Sillebak Kristensen, Inst. of Agroecology, Foulum, Aarhus University. Version 14. Edited: 19. Feb. 2017. 1.1. Plant cover and catch crops A catch crop, usually rape, oil radish or ryegrass, is sown for collecting nitrogen during the autumn and winter, and must be incorporated into the soil in the spring and is always followed by a spring sown crop. There are two levels of catch crops 1
If animal manure corresponding to more than 80 kg N/ha are applied, you have to establish catch crops in at least 14% of the catch crop base area (see below). If animal manure corresponding to less than 80 kg N/ha are applied, you have to establish catch crops in at least 10% of the catch crop base area (see below). You must always have catch crops in at least 4% of the area, irrespective of having 100% winter crops. There is a release of nitrogen from the incorporated catch crop, which has to be subtracted the N quota of the following crop: 25 kg N/ha if you have 14% catch crops and 17 kg N/ha if you have 10%. (see example below) Catch crop base area The percentage of area with catch crops is calculated from the catch crop base area, i.e., area with the following crops: Cereals (winter or spring), peas, spring or winter rape, faba beans, maize, mustard or sunflower. Table 1. DK norms for yield, fertilizer application and catch crop area. From (NaturErhvervstyrelsen 2016) Crop Effect Must on next the crop effect of previou s crop Coarse sandy (below 5 percent clay), JB 1 or 3, not irrigated Fine sandy 5-10 percent clay, not irrigated, JB 2 or 4 Below 10 percent clay, irrigated. JB 1-4 Loamy Sand (10-Sandy loam, Correction 15 percent more than 15 for clay), percent clay, JB yield** JB 5-6 7-10 kg N/ha yes/no Yield, kg N/ha kg N/ hkg Spring barley 0 Yes 44.0 144 51.0 139 56.0 162 63.0 147 67.0 153 increas 1,5 Compulsary catch crops 17/25 No - 0-0 - 0-0 - 0 0 *1 hkg = 100 kg **If a farmer can demonstrate a higher yield than the standard, he can incease the quota using the OrgFile= Tabel_1_1998_2017_isk67 Example with 14% catch crop followed by spring barley: If spring barley is sown in coarse sandy soils after incorporation of catch crops, it is not allowed to apply more than 119 kg N/ha (144 25 = 119). 2
1.2 N quota / N norms Table 2. DK norms for fertilizer application. Extracted from Table 1 in Vejledning om gødsknings- og harmoniregler, (NaturErhvervstyrelsen 2016) Table 1. DK norms for fertilizer application, 2016/17, NaturErhvervstyrelsen (2016) Crop Winter precipitation / N prognosis The above mentioned standards are corrected (by region) for winter precipitation; corrections are given just before the new season, and are made on the presumption that very wet winters leave less mineral soil N for the new season. This correction, referred to as N-prognosis, is based on 150 measurements of N-min in the Square Grid Net for Nitrate Investigation in Denmark, and associated model calculations. Harmony rules Effect Must the on next effect of crop previous crop be included Coarse sandy (below 5 percent clay), JB 1 or 3, not irrigated Fine sandy 5-10 percent clay, not irrigated, JB 2 or 4 Below 10 percent clay, irrigated. JB 1-4 The harmony rules prescribe maximum amount of animal manure to be applied per ha. According to the EU Nitrate Directive, the general maximum level is 170 kg N/ha. Only France is following this general rule; other countries have got exceptions for cattle farm allowing up to 230 kg N/ha providing a minimum proportion of the area is grassland or fodder crops. Loamy Sand (10-Sandy loam, Correction 15 percent more than 15 for clay), percent clay, JB yield** JB 5-6 7-10 kg N/ha yes/no Yield, kg N/ha kg N/ hkg Spring barley 0 Yes 44.0 144 51.0 139 56.0 162 63.0 147 67.0 153 increas 1,5 Winter barley 0 Yes 51.0 182 55.0 172 59.0 192 74.0 195 79.0 206 1,2 Rye 0 Yes 46.0 157 59.0 158 58.0 172 71.0 172 75.0 182 1,2 Winterwheat 0 Yes 49.0 167 63.0 173 67.0 194 81.0 200 86.0 213 1,5 Winterwheat for bread 0 Yes 49.0 213 63.0 222 67.0 244 81.0 253 86.0 266 1,7 Winter rape 23 Yes 29.0 203 37.0 215 37.0 215 42.0 223 44.0 226 1,5 Peas 23 No 46.0 0 46.0 0 46.0 0 46.0 0 46.0 0 0 Potatoes for starch 0 Yes 450 228 500 223 550 248 550 223 550 223 0,2 Potatoes, fresh 0 Yes 320 167 390 167 420 187 420 162 420 162 0,2 Sugar beets 3 Yes 450 133 500 123 500 138 620 125 680 131 0,1 Ryegrass for seed 23 No 12 170 12 170 12 170 12 170 12 170 0 SFU/ha kg N/ha SFU/ha kg N/ha SFU/ha kg N/ha SFU/ha kg N/ha SFU/ha SFU/ha Maize for silage 0 Yes 9900 167 9900 152 10900 182 10800 156 11300 163 0 Clover grass (below 50 % clov 95 No 6600 282 6800 284 8100 297 7100 287 7100 287 0 Grass without clover 23 No 7600 377 8100 387 9600 417 8600 397 8600 397 0 Permanent grass 23 No 3100 156 3100 156 3100 156 3100 156 3100 156 0 Onion 0 Yes - 165-150 - 165-140 - 150 0 Compulsary catch crops 17/25 No - 0-0 - 0-0 - 0 0 *1 hkg = 100 kg **If a farmer can demonstrate a higher yield than the standard, he can incease the quota using these OrgFile= Tabel_1_1998_2017_isk67 3
Table 3. EU rules for N-applications, updated in 2009. Application standard for Country Conditions manure Derogation Denmark Flanders Germany (kg total manure N /ha) Farms with > 70% grassland + forage crops - Granted (2009-2017) 230 - Applies to whole farm area - Manures: cattle Other situations, for cattle, sheep and goats 170 Grass; maize followed by grass 250 - Granted (1.1.2007-31.12.2010) Winter wheat+green manure crop, sugar and fodder - Manures: cattle (except fattening calves), horses, beets 200 goats, sheep, liquid fraction of pig slurry (these are called derogation manures ) Legume crops other than peas and beans 0 Crops with low N demand 1 125 Other crops 170 Grassland ( 4 cuts or 3 cuts + grazing) 230 Livestock Unit (LSU) (DK=DE) corresponds to 100 kg total N in the manure from storage, which means the Danish harmony rules expressed in LSU (DE) are: Table 4. Maximum allowance of manure applications in Denmark, - Granted (2006-2009) - Applies to resp. crop acreages - Manures: cattle Other situations 170 France All situations 170 - To date, no derogation was requested Netherlands Farms with > 70% grassland Other farms 170 1 Chichory, flax, carrots, shallots, onions, fruit OrgFile= Tabel_1_1998_2017_isk67 OrgSheet= Harmony LSU (DE)/ha/yr Farm type 1.7 LSU (DE) For manure the maximum limit is 1.7 LSU (DE)/ha/yr. 2.3 LSU (DE) Providing that more than 2/3 of the manure is cattle manure, and the more than 70% of the area is covered grass or fodder beets. Further, soils must analyzed every 3rd year for content of N and P. 1.3. Utilisation of animal manure - Granted (2006-2009) - Applies to whole farm area - Manures: cattle (except fattening calves), horses, The N fertilizer value (NFV) of manure is defined as the amount of N in the manure having the same effectiveness as carefully applied mineral N fertilizers expressed as a percentage of total N in the manure. The table below summarizes N fertilizer values of most frequently used manure types. 250 4
The values apply to the first year of application. Table Table 5. Nfertilizer value of animal manure in EU countries, updated in 2009. N fertilizer value of manure Cattle slurry Pig slurry Recommendations Legal (Action Programme) NL FL GE DK FR NL FL GE DK Arable land, spring, maize/potatoes/beets 50-55 55 70 55-70 55 60-65 60 50 70 Arable land, spring, winter wheat 40 55 70 45-55 60-65 60 50 70 Grassland, before 1st cut 45-50 55 70 45-50 50-60 60 60 50 70 Excreted on pasture 25 20 20 70 Arable land, spring, maize/potatoes/beets 70-75 65 60 70-75 60-75 60-65 60 60 75 Arable land, spring, winter wheat 55 65 60 65-70 60-70 60-65 60 60 75 Grassland, before 1st cut 45-55 65 60 60 50-65 60 60 60 75 Arable land, spring, maize/potatoes/beets 30 30 60 45 15-30 40 30 25 65 Solid cattle manure Solid chicken Arable land, spring, maize/potatoes/beets 50-55 55 50 65 45-65 55 30 30 65 manure Arable land, spring, maize/potatoes/beets 85-90 80-90 90 80 90 85 Liquid fraction after Arable land, spring, winter wheat 70 80-90 85-90 80 90 85 separation Grassland, before 1st cut 65-75 80-90 75-80 80 90 85 Solid fraction after separation, cattle Arable land, spring, maize/potatoes/beets 25 25 55 40 65 Solid fraction after Arable land, spring, maize/potatoes/beets 50 35 55 50 65 separation, pigs Compost Arable land, spring, maize/potatoes/beets 10 10 10-15 10 1 values as used in underpinning of Action Program (Mestdecreet), not explicit in Action Programme 2 used for deriving a fixed NFV value for situations of grazing (45% in 2009) 3 Values based on the recommendation of Thüringen for manures produced on the. farm. Different values apply for manures imported to the farm fil= Tabel_1_2002_2011_isk 1.4. Storage and spreading time. Table 6. Periods when application of manures and chemical fertilizers is allowed in Denmark. Bare soils winter Winter crop general Winter Oil seed rape and grass Liquid manures 1/2-1/6 1 1/2 1/6 1 1/2-1/10 Solid manures 1/11-1/6 1 No restriction No restriction Chemical fertilizers No restriction No restriction No restriction 1 Actually until harvest; in practice this means no later than 1/6 because manures cannot be applied later in most crops (besides grass). 5
Table 7. Conversion from animal to animal units (LSU) Animal type Unit Number of animals Tabel_1_1998_2017_isk67 for 1 LSU (DE) Cattle: 2017 Dairy cow, Frisian size 1 year-cow 0.75 Youngsters, 0-6 months, heavy race 1 year-animal 3.70 Heifer, 6-28 months, heavy race 1 year-animal 2.00 Heifer, 0-28 months, heavy race 1 year-animal 2.38 Male calves 0-6 months heavy race 1 prod. animal 8.50 Male calves 6 mdr.-slaughter (440 kg) heavy race 1 prod. animal 4.00 Male calves 0 mdr.-slaughter (440 kg) heavy race 1 prod. animal 2.72 Dairy cow, light race (Jersey) 1 year-cow 0.88 Youngsters, 0-6 months, light race (Jersey) 1 year-animal 5.00 Heifer, 6-25 months, light race (Jersey) 1 year-animal 2.70 Heifer, 0-25 months, light race (Jersey) 1 year-animal 3.25 Male calves 0-6 months light race 1 prod. animal 11.50 Male calves 6 mdr.-slaughter (440 kg 12,5 mdr.) light race 1 prod. animal 5.10 Male calves 0 mdr.-slaughter (440 kg 12,5 mdr.) light race 1 prod. animal 3.53 Sucler cow (400-600 kg ) 1 year-animal 1.60 Pigs: Sows with piglets (4 weeks ~ 7,2 kg) 1 yearsow 4.40 Piglets from 7,2 to 30 kg 1 prod. animal 208.00 Slaughter pigs from 30 to 102 kg 1 prod. animal 39.00 Poultry: Hense for eggproduction 1 year-animal 170.00 Slaughter chickens 30 days 4210.00 Slaughter chickens 35 days 1 prod. animal 3020.00 Slaughter chickens 45 days 1 prod. animal 1790.00 Other types: Sheep with lamb 1 year-animal 7.00 Horses 500-700 kg 1 year-animal Mink 1 year-female 29.00 6
Table 8. N, P and K in animal manure, translated from (NaturErhvervstyrelsen 2016) Bilag 2. Table 2. DK norm production of animal manure, 2016/2017 Animal and stable type Manure type Content kg nitrogen kg phospor us kg potassiu m (ab storage) 1 dairy cow; heavy race, 10356 liter milk Tie stall Solid manure 69.9 18.8 29.4 + urine 58.1 2.1 73.3 Tie stall with slurre Slurry 142.4 20.9 103.7 Bedding barn with solide floor Slurry 132.2 20.7 100.0 Bedding barn with channals Slurry 137.3 20.7 100.0 Deep Litter Deep litter 152.0 23.1 153.1 1 sow with 27,2 piglets to 7,4 kg Individual tiedup, slatted Slurry 14.3 3.7 6.9 loose system, slatted Slurry 14.9 3.7 7.4 10 piglets, 7,4-32 kg Slatted Slurry 4.5 1.2 2.8 10 slaugther pigs, 32 107 kg Partly slatted, with 25-49% solide floor Slurry 25.5 6.4 14.3 OrgFile= Tabel_1_1998_2017_isk67 7
Table 8. N and P content of selected crops, se in Danish (Møller et al. 2005) Feed item DM% Crude protein. % of DM NEL20 1) Energy Kg feed P K MJ pr. kg SFU per kg per SFU g pr kg DM g per kg DM DM DM Cash crops Oats 85.0 10.2 1.79 11.2 6.2 0.91 1.29 3.6 5.5 Spring barley 85.0 10.2 1.47 9.2 7.5 1.11 1.06 3.8 5.7 Winter barley 85.0 10.2 1.47 9.2 7.5 1.11 1.06 3.4 5.9 Wheat 85.0 10.2 1.36 8.5 7.8 1.20 0.98 3.5 5.8 Rye 85.0 9.6 1.31 8.2 7.7 1.17 1.00 3.2 5.6 Rice 86.0 9.7 1.51 9.4 0.0 1.03 1.13 Maize 87.5 9.6 1.26 7.9 8.0 1.22 0.94 3.2 4.0 Broadbeans 86.4 31.1 4.25 26.5 0.0 1.17 0.99 6.8 16.0 Soyabeans 90.4 41.1 4.50 28.1 0.0 1.46 0.76 5.5 19.6 Winterrapeseed 92.5 19.4 1.65 10.3 0.0 1.88 0.57 7.6 10.0 Hempseed 92.0 5.7 0.57 3.6 0.0 1.57 0.69 1.7 8.9 Peas 85.2 24.0 3.01 18.8 8.4 1.28 0.92 4.6 12.0 Concentrate Rapeseed meal, 00, 4% fat 88.2 38.8 5.75 35.9 6.6 1.08 1.05 12.9 15.0 Soyabean meal 87.6 48.7 5.71 35.7 8.3 1.36 0.84 7.6 27.0 Sugar beet 22.0 5.9 0.96 6.0 6.5 0.98 4.62 1.7 21.0 Potatoes 24.0 9.2 1.46 9.1 7.7 1.01 4.13 2.1 20.0 Grass pellets, plus 92.0 18.0 3.96 24.7 5.1 0.73 1.49 3.8 29.0 Cane molasses (treacle) 73.0 5.5 1.03 6.5 6.4 0.85 1.61 0.7 49.0 Sunflower seed meal, partially hu 89.0 41.7 6.22 38.9 6.7 1.07 1.05 12.6 17.0 Fodder urea 288.0 Rouhage Hay 84.0 11.2 2.78 17.3 5.1 0.65 1.84 2.7 22.0 Spring barley straw 85.0 4.0 2.81 17.5 2.5 0.23 5.16 0.9 20.0 Maize whole crop silage 34.7 7.7 1.40 8.7 6.5 0.88 3.27 2.4 11.0 Barley whole crop silage 34.0 10.1 2.21 13.8 5.7 0.73 4.02 2.9 17.0 Wheat - wholecrop (early 40.0 8.8 2.04 12.7 0.0 0.69 3.62 2.6 13.0 Wholecrop barley (beginning of 31.0 15.6 3.14 19.6 0.0 0.80 4.05 3.7 30.0 Barley - peas, silage 20% peas 33.0 11.1 2.33 14.6 0.0 0.76 #VALUE! 2.9 16.0 Lucerne- silage, low fodder 43.0 18.5 4.90 30.6 0.0 0.60 3.85 3.7 31.0 Grass silage 36.0 16.2 3.15 19.7 5.8 0.82 3.37 3.9 30.0 Grass-clover silage 36.0 17.3 3.34 20.9 6.5 0.83 3.35 3.8 29.0 Grass grazed 17.0 22.0 3.69 23.0 6.5 0.95 6.16 3.4 29.0 Grass-clover grazed 17.5 24.0 3.95 24.7 6.6 0.97 5.87 4.0 29.0 1) Net energy, see http://norfor.info/ fil= Norm_HG_2000_2012.xlsx Sheet= FM K_UK 2) DTU Fødevaretabellen % N of SFU % Protein of SFU The yield of straw (85 % dry matter) is approximately 55 % of the grain yield for barley, wheat, oat, and triticale, and 90 % for rye and rape. 8
2. Rules related to extension of the animal production Ib Sillebak Kristensen, Dept. of Agroecology, Foulum, Aarhus University. Foulum, Feb. 2017 The written material about the rules to follow if a farmer is applying for an extension of his production is in Danish on the homepage of Ministry of Environment (http://www.husdyrgodkendelse.dk). An English summary of important parts is given here in part II. When a farmer wants to extend the animal production and send an application requirements concerning ammonia volatilization, phosphorus surplus, and nitrate leaching have to be considered. These requirements are shortly described below 2.1 Ammonia volatilization The environmental assessment is carried out in three steps: General requirements Buffer zone requirements Requirements related to other sensitive areas than those included in buffer zones. Buffer zone requirements Experiments have shown that deposition of ammonia decrease with the distance from the stable from where it was emitted. 8 Deposition, kg N/ha (9 weeks) 7 6 5 4 3 2 1 Buffer zone I Buffer zone II 0 0 200 400 600 800 1000 1200 Distance from stable, m Figure 1. Ammonia decrease with distance from stable emission. 9
Two buffer zones have been defined: Distance to vulnerable/sensitive areas < 300 m = buffer zone I Distance to vulnerable/sensitive areas 300-1000 = buffer zone II Buffer zone I: No increase in ammonia emission is allowed Buffer zone II: - If more than 2 farms (applying farm + more than 1) are in the zone emissions may increase by a maximum of 0.3 kg N/ha. Other requirements - If 2 farms (applying farm + 1) are in the zone emissions may increase by a maximum of 0.5 kg N/ha. - If only the applying farm is in the zone emissions may increase by a maximum of 0.7 kg N/ha. If other sensitive areas or plant species than those included in buffer zone requirements, the municipality can add special requirements. 2.2. Instruments (Virkemidler) for reducing ammonia emission Acidification of slurry Biological or chemical air cleaner Cover on slurry tank Floating barrier in slurry tank 10
Figure 2. Map indicating sensitive and protected areas in Denmark, incl. buffer zone I and II, see http://arealinformation.miljoeportal.dk/distribution/ 2.3 Phosphorus application Requirements for P are based on calculations of P surplus (input with manure removed with harvested crops) in the present situation compared to the applied situation. The max. application in 2017 is 30-43 kg P/ha/year (Thysen 2017) The application are depending on which P class the farm is situated in (see map below) Table 9. P application dependent of soil P-status. (Thysen 2017) Phosphorus value 1) (Pt) Less than 3 Requirements for P norm-application Max. application can be increased by 8 kg P/ha per Pt-unit below Pt=3 3 to 4 Max. application can be increased by 2 kg P/ha per Pt-unit below Pt=3 1) Pt is a value expressing the part of the P, which is dissolved in soil water, and therefore potential leaching risk. 2.4. Instruments (Virkemidler) for reducing phosphorus leaching/runoff Increase the area (bye more land) More efficient feeding 11
2.5. Nitrate leaching surface water In year 2019 a new regulation for nitrate leaching will be introduced. Until 2019 the nitrate leaching on farm level, i.e., average leaching in kg N/ha, is calculated with model www.farm-n.dk In Danish see (Vinther et al. 2007). In English see tab= documentation after Farm-N > English > Demo login Table 10. Nitrate classes, in Danish se http://www2.mst.dk/wiki/husdyrvejledning.nitrat%20%28overfladevand%29.ashx#husdyrvejledning.nitrat-overfladevand- Vurdering_FarmN_18: Reduction potential (%) of the nitrate on its way from root zone to surface water: Very sensitive or vulnerable area Medium sensitive or vulnerable area Other areas 0-50 0.7 LSU/ha. Nitrate class 3 51-75 0.91 LSU/ha. Nitrate class 2 76-100 1.4 LSU/ha 1.19 LSU/ha Nitrate class 1 1.4 LSU/ha 1.4 LSU/ha 1.4 LSU/ha 1.4 LSU/ha 1.4 LSU/ha 12 Figure 4. Nitrate classes in Denmark. Se
Distribution of nitrate classes Requirements for the nitrate classes: : Nitrate class 1: Nitrate class 2: Nitrate class 3: The leaching (kg N/ha) must not exceed the leaching at general harmony rules; i.e., the leaching that takes place from animal manure corresponding to 1.4 AU (DE) for pig manure or 1.7 AU (DE) for cattle manure. The leaching (kg N/ha) must not exceed the leaching that will take place at 85 % of general harmony rules; i.e., the leaching that takes place from animal manure corresponding to 1.2 AU (DE) for pig manure or 1.4 AU (DE) for cattle manure. The leaching (kg N/ha) must not exceed the leaching that will take place at 65 % of general harmony rules; i.e., the leaching that takes place from animal manure corresponding to 0.9 AU (DE) for pig manure or 1.1 AU (DE) for cattle manure. The leaching (kg N/ha) must not exceed the leaching that will take place at 50 % of general harmony rules; i.e., the leaching that takes place from animal manure corresponding to 0.7 AU (DE) for pig manure or 0.85 AU (DE) for cattle manure. Example with a pig farm where fields are in different nitrate classes; 25 % of the area in nitrate class 3 and 75 % in nitrate class 0: The leaching (kg N/ha) from this farm must not exceed the leaching that will take place at a pig manure load corresponding to 0.7x0.25 + 1.4x0.75 = 1.225 AU. Nitrate class 3 (0,7 AU/ha) (1.4 AU/ha) (1.4 AU/ha) (1.4 AU/ha) If the area is classified as a nitrate sensitive groundwater area, the nitrate concentration in the water leaving the root zone must not increase, if the concentration in the present situation is more than 50 mg/l. Nitrate leaching groundwater Instruments (Virkemidler) for reducing nitrate leaching More catch crops than required by the general rules Reduced N quota Change of standard crop rotation 13
Figure 5. Nitrate sensitive groundwater areas. See last page on http://mfvm.dk/fileadmin/user_upload/fvm.dk/dokumenter/landbrug/indsatser/foedevare- _og_landbrugspakke/aftale_om_foedevare-_og_landbrugspakken.pdf 3. Litteratur. Litteraturliste Kristensen, I. S. (2016). Danish rules and key values related to fertiliser and animal manure in general, updated to year 2010/2011. See http://pure.au.dk/portal/files/86942578/fert_and_ext_rules_2010_2011_isk7.docx Dept. of Agroecology. Aarhus University: 1-16. Møller, J., R. Thøgersen, M. E. Helleshøj, M. R. Weisbjerg, K. Søegaard and T. Hvelplund (2005). "Fodermiddeltabel 2005, see http://www.landbrugsinfo.dk/kvaeg/filer/rap112.pdf.." Rapport nr. 112: 1-65. NaturErhvervstyrelsen (2016). Vejledning om gødsknings- og harmoniregler. 2016/17. se http://naturerhverv.dk/landbrug/goedning/goedningsregnskab/#c12333 https://www.retsinformation.dk/forms/r0710.aspx?id=183364 og http://naturerhverv.dk/fileadmin/user_upload/naturerhverv/filer/landbrug/goedningsregnskab/vejledning_om_goedsknings- _og_harmoniregler_nyeste.pdf. Miljø- og Fødevareministeriet. NaturErhvervsstyrelsen.: 1-180. Thysen, H. R. (2017). Sådan tilpasser man sig de nye fosforkvoter. Plantekongres 2017. se https://www.landbrugsinfo.dk/planteavl/plantekongres/sider/pl_plk_2017_res_47_2_hans_roust_thysen_3076.pdf og https://www.landbrugsinfo.dk/planteavl/plantekongres/filer/pl_plk_2017_47_2_hans_roust_thysen.pptx. Plantekongres. Herning. Vinther, F. P., I. S. Kristensen and M. S. Jørgensen (2007). Beregningsmetode for kvælstofudvaskning. Se model på http://130.226.173.223/farmn_new/dokumentation/beregning%20af%20n-udvaskning%20med%20farmn.pdf. 14