Calculating regional gross nutrient balances Anne Miek Kremer & Kees Olsthoorn from statistical and administrative data Statistics Netherlands A Working Program

Main Flows in Nitrogen Balances

Livestock manure

Two regions feed rations for ruminants Silage grass Silage maize

Excretion coefficients and feed balances What livestock consumes must result either in urine/manure or in product (milk, meat etc). Ruminants: regional feed balances to calculate excretion coefficients Other livestock: national averaged excretion coefficients

Regional feed balances for ruminants Feed available for ruminants in the region: Silage grass and hay: annual survey Silage maize: annual survey Concentrates: national sales statistics, index numbers Meadow grass: unknown, calculated in the feed balance Dairy cows: consumption of conserved roughage and concentrates is variable Other ruminants: consumption of conserved roughage and concentrates based on norms Feed is expressed in VEM (measure for the feeding value) Feed requirements Dairy cows: feed requirement is depending on milk production Other ruminants: standard feed requirements

Regional feed balances for ruminants kVEM per animal ConcentratesSilage grass and hay Silage maize Meadow grass Dairy cows x???? Other Ruminants xxxx? Totalxxx? kVEM per animal ConcentratesSilage grass and hay Silage maize Meadow grass 1 Dairy cow 6000 =? + ? 1 Other cow 3000 = ? Total ? kVEM per animal ConcentratesSilage grass and hay Silage maize Meadow grass 1 Dairy cow 6000 =? + ? 1 Other cow 3000 = Total ? kVEM per animal ConcentratesSilage grass and hay Silage maize Meadow grass 1 Dairy cow 6000 = ? 1 Other cow 3000 = Total ? kVEM per animal ConcentratesSilage grass and hay Silage maize Meadow grass 1 Dairy cow 6000 = Other cow 3000 = Total

Problems with the feed balance for ruminants Two regions: Very low consumption of meadow grass by dairy cows NUTS-2 regions: Negative consumption of meadow grass by dairy cows in some regions

Underestimation of feed requirements Underestimation of feed requirements of dairy cows Underestimation of feed requirements of other ruminants Overestimation of VEM-value of meadow grass

Overestimation of silage maize Maize available for ruminants in year t = production year t-1 Not taken into account: Exports of maize Energy production Stock changes 14 ton ds/ha CBS, 12,5 ton ds/ha other research

Overestimation of silage grass and hay Silage grass and hay available year t = production year t + stock changes Response silage grass harvest: Grass in pit or field production? Response grassland area in use: Grassland survey > FSS Raising results: 1) production region survey * grassland area region survey (FSS) total grassland area region (FSS) 2) average production per ha region * total grassland area region (FSS) Underestimation of grassland production (meadow grass, silage grass, hay)

Other problems effecting feed availability Consumption of grass by animals not counted in the FSS FSS horses; reality between horses Consumption of concentrates by other ruminants in pasture season

Allocation of feed between regions Export and import of feed between regions Regional differences in feed rations of other ruminants Regional differences in intake of concentrates by dairy cows

Conclusions Expert discussion on problems, causes and solutions Improvement of excretion coefficients for ruminants for two regions Data on export and import of feed between regions Option 1: calculating excretion coefficients on the NUTS-2 level for dairy cows. Option 2: calculating excretion coefficients for two regions for ruminants

Artificial fertilisers Regional use of fertilisers: fertiliser crop coefficients and crop areas FSS Available data: Derogation farms and risk farms registration Manure transports registration Other organic fertiliser transports registration FSS Soilstatistics

Calculating the use of artificial fertiliser per farm Derogation and risk farms: Use of artificial fertiliser = stockchanges + supply - removal Other farms: Use of artificial fertiliser = norm – use of animal manure and other organic fertilisers Use of animal manure = (production +) supply – removal Use of other organic fertilisers = supply – removal Norms on the use of fertilisers and manure stated in the law: Maximum use of animal manure (in kg N) per ha Maximum use of kg N per ha Maximum use of kg P 2 O 5 per ha