estimation of n-surplus and -losses in denmark using ’farm-n’

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Estimation of N-surplus and -losses in Denmark using ’Farm-N’

Dept. for Agroecology, Danish Institute of Agricultural Sciences

www.Farm-N.dk

Ib Sillebak Kristensen

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Motivation

• Legislation on the losses of N to the environment – nitrates (EU Nitrates Directive)

– ammonia (EU National Emissions Ceilings Directive)

– nitrous oxide (Kyoto agreement)

• Farm N surplus is good environmental indicator

• Farm N surpluses can be calculated fairly accurately and reliably

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Herd Animals

Milk

Manure

Manure

Manurestorage

Manure from storage

Cash crops

Manure fromgrazing

Input-output = Farm gate surplus

N2-fixation

Fertilizer

Field

Concentrate

GrazingSilage, grain& straw (net)

Nitrogen flow on farm

Fields

Cattle / Pigs

Inputs Outputs

Losses

Farm

N-flows, [kg N/ha] +/- standard deviation

Farm Dairy LSU/ha= 1,9Inputs Outputs

Herd , 190 LSU 48 +/- 1 MilkFeed 105 +/- 4 N-surplusHerd = 204 +/- 5

N-effHerd = 61 / 260 = 23% 13 +/- 1 MeatBedding 4 +/- 1

Total 155 +/- 29N-lossManure 24

179 +/- 28

Field = 100 HaN-surplusField = 143 +/- 41

Fertilizer 72 +/- 4 N-effField = 155 / 299 = 52% 0 +/- 0 Crops

Fixation 32 +/- 8

Deposition 16 +/- 5

Total inputs 228 +/- 11 N-surplusFarm gate = 168 +/- 11 Total outputs 61 +/- 2

N-effFarm gate = 61 / 228 = 27%

N-flows, [kg N/ha] +/- standard deviation

Farm Dairy LSU/ha= 1,9Inputs Outputs

Herd , 190 LSU 48 +/- 1 MilkFeed 105 +/- 4 N-surplusHerd = 204 +/- 5

N-effHerd = 61 / 260 = 23% 13 +/- 1 MeatBedding 4 +/- 1

Total 155 +/- 29N-lossManure 24

179 +/- 28

Field = 100 HaN-surplusField = 143 +/- 41

Fertilizer 72 +/- 4 N-effField = 155 / 299 = 52% 0 +/- 0 Crops

Fixation 32 +/- 8

Deposition 16 +/- 5

Total inputs 228 +/- 11 N-surplusFarm gate = 168 +/- 11 Total outputs 61 +/- 2

N-effFarm gate = 61 / 228 = 27%

Reliable

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

The tool

• A whole-farm model for N flow

• Focus on the interaction between crop and livestock production

• Static model, results represent average situation

• Deterministic, so the same input produces the same output

• Underlying assumption: Nutrient quota used to regulate management.

• Desired feature: Best possible management

• As simple as possible

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Farm Field Rotation Cattle Pig Manure Balance Results Doc

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Field

Rotation 1Arable rotation with grass/clover ley

Rotation 2Continuous maize

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Crop rotation

Optimized crop rotation

with respect to- maximum yield- minimum N-surplus

subject to- repeating crop sequence- same crop acreage each year- ad hoc rules

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Cattle

BreedCategoriesNumbersFeeding regimeProduction levelEfficiencyHousing type

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Pigs

CategoriesNumbersFeeding regimeProduction levelEfficiencyHousing type

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Manure

Optimized manure application

with respect to- maximum utilization

subject to- fields allowed to receive manure- crop-specific utilization rates

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Balance of field – livestock interactions

Produced - used - losses + bought – sold = 0

System definitions

Technical coefficients

Rest

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Results

Farm-N

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Results

Distribution of Farm gate N-surplus = 168 kg N/ha

Lost of input7%4%1%7%2%3%5%

Farm-N

N-balances on idealized DK dairy farm, 1.9 LSU/ha irrigated sand.

DK dairy

Grass/clover

Maize

Area use, % low N-eff high N-eff

-grass/clover 30% 70% 30%

-maize 20% 0% 35%

N-import, N ha-1

-feed 109 91 79

-mineral N 72 100 80

-fixation + dep. 48 89 47

N-export, N ha-1 -61 -61 -61

Farm N-balance 168 220 145

N-losses on idealized DK dairy farms, irr. sand. kg N ha-1

DK dairy

Grass/ Clover

Low N-eff

Maize

High N-eff

Farm N-balance 168 220

145

N-losses

-amm. vol. 31 34 28

-denitrification 17 23 18

-acc. soil-N 49 84 53

-leaching 71 79 47

N-losses on idealized DK dairy farms, irr. sand, kg N ha-1

DK dairy

Grass/ clover

low N-eff

Maize

high N-eff

Farm N-balance 168 220 145

N-losses

-amm. vol. 31 34 28

-denitrification 17 23 18

-acc. soil-N (low C/N) 49 (38) 84 (73) 53 (41)

-leaching(low C/N) 71 (82) 79 (89) 47 (57)

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Conclusions

• A web-based prototype is available• Uses data available to the farmer• Negotiations with Danish authorities on its

use for screening environmental impacts

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

Future developments

• Farm P balance ?• Data import from farm management programs

?• Online collaboration on system definitions

(farmer, adviser, regulation authority) ?• Internationalisation ?

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

www.farm-N.dk/FarmNTool

Herd Animals

Milk

Manure

Manure

Manurestorage

Manure from storage

Cash crops

Manure fromgrazing

Input-output = Farm gate surplus

N2-fixation

Fertilizer

Field

Rouhage+ grain for fodder

Straw

Storage:-rouhage-grain-straw

Concentrate

GrazingSilage, grain& straw (net)

N-flows, [kg N/ha] +/- standard deviation

Farm Dairy LSU/ha= 1,9Inputs High C/N Outputs

Herd , 190 LSU 48 +/- 1 MilkFeed 105 +/- 4 N-surplusHerd = 204 +/- 5

N-effHerd = 61 / 260 = 23% 13 +/- 1 MeatBedding 4 +/- 1

Total 155 +/- 29Grazed 45 +/- 13 N-lossManure 24Conserved 85 +/- 25Grain 26 +/- 2 0 +/- 0 Manure

179 +/- 28

Manure 0 +/- 0 Field = 100 Ha 0 +/- 0 GrainN-surplusField = 143 +/- 41

Fertilizer 72 +/- 4 N-effField = 155 / 299 = 52% 0 +/- 0 Crops

Fixation 32 +/- 8

Deposition 16 +/- 5

Total inputs 228 +/- 11 N-surplusFarm gate = 168 +/- 11 Total outputs 61 +/- 2

N-effFarm gate = 61 / 228 = 27%

N-flows, [kg N/ha] +/- standard deviation

Farm Max grass/clover LSU/ha= 1,9Inputs Outputs

Herd , 190 LSU 48 +/- 1 MilkFeed 55 +/- 2 N-surplusHerd = 207 +/- 3

N-effHerd = 61 / 261 = 23% 13 +/- 1 MeatBedding 7 +/- 1

Total = 205 +/- 42Grazed = 89 +/- 26 N-lossManure 21

Conserved = 111 +/- 33Grain = 6 +/- 1 0 +/- 0 Manure

186 +/- 29

Manure 0 +/- 0 Field = 100 Ha 0 +/- 0 GrainN-surplusField = 169 +/- 55

Fertilizer 100 +/- 5 N-effField = 205 / 375 = 55% 0 +/- 0 Crops

Fixation 73 +/- 18

Deposition 16 +/- 5

Total inputs 251 +/- 20 N-surplusFarm gate = 191 +/- 20 Total outputs 61 +/- 2

N-effFarm gate = 61 / 251 = 24%

N-flows, [kg N/ha] +/- standard deviation

Farm Max. maize & W/C LSU/ha= 1,9Inputs Outputs

Herd , 190 LSU 48 +/- 1 MilkFeed 95 +/- 4 N-surplusHerd = 207 +/- 4

N-effHerd = 61 / 260 = 23% 13 +/- 1 MeatBedding 7 +/- 1

Total 165 +/- 40Grazed 25 +/- 7 N-lossManure 25Conserved 133 +/- 39Grain 8 +/- 1 0 +/- 0 Manure

182 +/- 29

Manure 0 +/- 0 Field = 100 Ha 0 +/- 0 GrainN-surplusField = 144 +/- 30

Fertilizer 80 +/- 4 N-effField = 165 / 309 = 53% 0 +/- 0 Crops

Fixation 31 +/- 8

Deposition 16 +/- 5

Total inputs 230 +/- 11 N-surplusFarm gate = 169 +/- 11 Total outputs 61 +/- 2

N-effFarm gate = 61 / 230 = 26%

N-flows, [kg N/ha] +/- standard deviation

Farm Arable, irrigated LSU/ha= 0,5Inputs Outputs

Herd , 50 LSU 0 +/- 0 MilkFeed 86 +/- 3 N-surplusHerd = 55 +/- 4

N-effHerd = 31 / 86 = 36% 31 +/- 1 MeatBedding 0 +/- 0

0 +/- 0N-lossManure 9

0 +/- 0 Manure

46,3 +/- 7

Manure 0 +/- 0 Field = 100 Ha 90,6 +/- 9 GrainN-surplusField = 92 +/- 14

Fertilizer 119 +/- 6 N-effField = 91 / 183 = 50% 0 +/- 0 Crops

Fixation 2 +/- 0

Deposition 16 +/- 5

Total inputs 223 +/- 9 N-surplusFarm gate = 101 +/- 12 Total outputs 121 +/- 9

N-effFarm gate = 121 / 223 = 55%

N-flows, [kg N/ha] +/- standard deviation

Farm Pig, sand LSU/ha= 1,4Inputs Outputs

Herd , 140 LSU 0 +/- 0 MilkFeed 244 +/- 10 N-surplusHerd = 155 +/- 10

N-effHerd = 89 / 244 = 36% 89 +/- 4 MeatBedding 0 +/- 0

0 +/- 0N-lossManure 25

0 +/- 0 Manure

130 +/- 21

Manure 0 +/- 0 Field = 100 Ha 90,8 +/- 9 GrainN-surplusField = 110 +/- 23

Fertilizer 54 +/- 3 N-effField = 91 / 201 = 45% 0 +/- 0 Crops

Fixation 2 +/- 0

Deposition 16 +/- 5

Total inputs 315 +/- 11 N-surplusFarm gate = 136 +/- 15 Total outputs 180 +/- 9

N-effFarm gate = 180 / 315 = 57%

Ministry of Food, Agriculture and Fisheries

Danish Institute of Agricultural Sciences

http://www.Farm-N.DK/

Litteraturliste 

Berntsen, J. and Petersen, B. M. 2005: C-TOOL, Danish version see http://web.agrsci.dk/jbe/bin/ctool.html. Jørgensen, M. S., Detlefsen, N., and Hutchings, N. J. 2005: FarmN: A Decision Support Tool for Managing Nitrogen Flow at the Farm Level. EFITA (European Federation for Information Technology in Agriculture, Food and the Environment) konferencen, Vila Real, Portugal, 25.-27. juli-2005. http://130.226.173.223/farmn/FarmNTool.pdf 1-7. Kristensen, I. S. 2005a: Nitrogen balance from cash crop farms (2002). http://www.lcafood.dk/processes/agriculture/N_balance_cash_crop_farms_2002.htm. Kristensen, I. S. 2005b: Nitrogen balance from dairy farms (2002). http://www.lcafood.dk/processes/agriculture/N_balance_dairyfarms_2002.htm#table_1. Kristensen, I. S. 2005c: Nitrogen balance from pig farms (2002). http://www.lcafood.dk/processes/agriculture/N_balance_pigfarms_2002.htm. Kristensen, I. S. 2005d: Uncertanties on Farm Gate N-balances, see. http://www.agrsci.org/afdelinger/forskningsafdelinger/jpm/medarbejdere/isk/oversigtsside_med_publikationer. Kristensen, I. S., Detlefsen, N., Hutchings, N., and Petersen, B. M. 2005: Documentation of the used coefficients in Farm-N. http://130.226.173.223/farmn/Documentation%20of%20the%20used%20coefficients%20in%20Farm.pdf. Petersen, B. M. and Berntsen, J. 2003: The turnover of soil organic matter on different farm types. http://www.darcof.dk/enews/sep03/orgmat.html. DARCOF.eNews. September 2003.