1. Calculating regional gross nutrient balances
from statistical and administrative data
A Working Program
Cor van Bruggen & Kees Olsthoorn
Statistics Netherlands

2. Nitrogen and phophorus surplus on agricultural soils, 1975-2006
Long time experience with nutrient balances largely from statistical data on the national level: c. 25 years experience, data available from 1970 until now.
National policies have caused relative large decreases in mineral surpluses. Details are available on the SN-website.
However, loss of N and P are still relatively large: Nitrogen: 235 kg N/ha (including volatile N losses) / Phosphorus: 50 kg P2O5/ha.

3. Main Flows in Nitrogen Balances
Main flows of nitrogen (phosphorus) in agriculture: focus on the input flows of fertilizers and livestock manure and on the output flow of fodder maize and grassland which are closely connected to the manure production of ruminants.
Regional data for nitrogen fixation (crop areas * fixation coefficients), atmospheric deposition and marketed crops are routinely available from agricultural statistics.

4. The use of nitrogen (kg N/ha) from animal manure in the Netherlands (NUTS-2)
First focus on animal manure: NUTS-2 data available now from number of animals (FSS) and nationally averaged excretion coefficients. The only more sophisticated regionalisation comes from the excretion coefficients of ruminants which are detailed into two major regions for the Netherlands: northwest with a dominant (silage) grass ration and southeast Netherlands with a dominant silage maize ration. Secondly data on transports of manure at the postal code level are taken into account in these actual calculations.

5. Two region feed balances for ruminants
Silage grass
Rough regionalisation of the Netherlands for two feed rations for ruminants in the Netherlands. TAPAS-research of some years ago has shown that significant improvement can be achieved only by specifation of these two regions into more detail: TAPAS 2001 report of Tromp et al.: Five region feed balances for ruminants in the Netherlands.
Silage maize

6. Cattle density on grassland and maize land
From table 3 of this report it can be seen that 5 different regions can be distinguished on the basis of cattle density with respect to grass land and maize land. These regions are a breakdown of the forementioned two regio division of the country.

7. Ruminants excretion coefficients for five regions5
1 = North Western Meadow area
2 = Eastern and Central Meadow area
3 = Western Meadow area
4 = Southern Cattle Breeding area
5 = Remaining areas 1 5 2 3
TAPAS 2001 study showed erratic results (negative pasture grass consumption in one region in one year) for the grass and maize balances for years around Objectives of this study: close inspection and specification of basic data, also for recent years, to improve and actualize the results of the feed balances from the Tapas-2001 study.
Second objective: calculate excretion coefficients from the 5-region-feed balances data and transfer these 5-region excretion coefficients to the NUTS-2 level. 5 5 4 5

8. From five regions excretion coefficients to NUTS-2 regions5
1= North Western Meadow area
2 = Eastern and Central Meadow area
3 = Western Meadow area
4 = Southern Cattle Breeding area
5 = Remaining areas 1 5 3 2
Transposition of five region manure excretion data to the NUTS provinces level. 5 4 5 5

9. Inorganic fertilizers
Available data:
Usage data on the national level
Usage data on the farm level for a select group of farms
Usage data at the farm/crop level from FADN
For inorganic fertilizers several data sources are available. The usage data on the farm level for a select group of farms has not yet been disclosed and/or used in calculations. The objective of this study is to combine and integrate the data from the various sources into regionally relevant fertilizer usage coefficients per main crop. By combination of the coefficients with the relevant regional crop areas, the usage of fertilizers on agricultural soils can be approximated.

10. Improve and actualize data for the five region feed balances
Summary of main objectives:
Improve and actualize data for the five region feed balances
Transpose feed data into excretion coefficients
Transpose five region excretion coefficients into NUTS-2 regions
Integrate data on fertilizers into relevant crop coefficients