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02 Calculation Method

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luFrVa edited this page Feb 6, 2025 · 23 revisions

How to Calculate a Nutrient Balance

A nutrient balance can be calculated by using the following Rest-API-endpoints:

These endpoints are each further splitted into separate endpoints for extended nutrient balance and a SuisseBilanz calculation (See Difference between Extended Nutrient Balance & SuisseBilanz).

For calculation a valid JSON-request body needs to be posted to the specific endpoint. The result of the calculation is transmitted inside the JSON-response body after a successful post request.

Calculation Process

The calculation method is made up of nutrient cycle (NC) and additional module (AM) calculations.

The calculation processes in the NäBi service are organised sequentially as follows: Start with the nutrient requirement calculation farmyard manure cascade & nitrogen utilisation rate calculation, which can be preceded by AM's such as IMPEX (import-export balance) and LK (linear correction). Subsequently plant nutrient requirement is calculated. Before the final nutrient requirement can be balanced with the nutrient requirement, correction of the calculated nutrient accumulation via emission-modifying factors is follows.

Nutrient Cycle (NC)

The Nutrient cycle is made up of nutrient accumulation and a plant nutrient requirement calculation.

Nutrient Accumulation

The nutrient accumulation is calculated from the animal excrement via the farmyard manure cascade. Emission-modification factors as well as the supply and dispense of farmyard manure follow the calculation before nitrogen utilisation rate if calculated for the farmyard manure accumulated on pasture or applied to the field. For recycling and mineral fertiliser only emission and utilisation rate during field application is calculated.

Nutrient accumulation is calculated via the following inputs:

Nutrient Requirement

Plant nutrient requirement calculation, is calculated using inputs for fodder balance and information on cultivation categories.

Nutrient requirement is calculated via the following inputs:

Nutrient Balance

Plant-available nitrogen is subsequently balanced with nutrient requirement of cultivation to result in the nutrient balance. Nutrient accumulation and requirement are automatically balanced and do not need further input for balancing.

Additional Modules (AM)

The Additional Modules calculate nutrient accumulation from animal lifestock based on either IMPEX or LK. AM can be used for the following two use cases

  • Send yearly proof of IMPEX or LK to cantonal enforcement -> Calculation of AM without calculating NC
  • Use result of IMPEX or LK for calculation of nutrient balance -> Calculation of AM in addition to calculating NC

Calculation Request Logic

Technical properties of request structure, as well as master data is fully described inside the technical openAPI documentation. Dependencies of request input is described within the following chapters of this wiki:

Input Validation

Transmitted input fields determine not only the constants which are chosen for the nutrient balance calculation but also the methodology being used for different calculation steps. Several input fields are specific for animalCategoryPRIF and stableSystem. Depending on which animalCategoryPRIF and stableSystem are chosen, different constants are chosen and alternative calculation steps will be carried out. Errors do only appear, for fields where conditions for dependency are not met. Fields which are methodolocially not relevant for a certain animalCategoryPRIF or a certain stableSystem are simply ignored by the NBS.

e.g.

For stableSystem of the zoologicalAnimal bovine an input for the field stableManureRemovalFrequency does technically make no sense, as stableManureRemovalFrequency is only methodologically relevant for stableSystem of the zoologicalAnimal poultry. No error occurs, the field is simply ignored.

For stableSystem of the zoologicalAnimal bovine hasStableDeepLitter and hasStableManureAndSlurryProduction are both set to true. Both fields are methodologically relevant for stableSystem of the zoologicalAnimal bovine but can not be both true as the calculation method does not allow it. An error occurs.

Master Data for Input

Request input types string(code) and number(id) correspond to a defined selection of master data. Every input possibility for master data can be requested from the NBS by GET-Request. For explanations how to retrieve master data see Retrieve master data for calculation input.

Difference between Extended Nutrient Balance and SuisseBilanz

While SuisseBilanz (SuiBi) corresponds to the calculation methodology, which is relevant to enforcement, Extended Nutrient Balance (ExBi) corresponds to the full nutrient accumulation calculation, which is not relevant to enforcement. Thus ExBi methodology can only be used to calculate a planning balance. SuiBi methodology is simplified by fixing certain input parameters by using default values. The proof of SuiBi makes it possible to check whether parts of the requirements of the Proof of Ecological Performance are fulfilled and thus whether the associated direct payments to the farms are released or not.

Differecce in calculation request

ExBi and SuiBi calculation request are separated via different endpoints. Data input objects between ExBi and Suibi differ, as SuiBi methodology is a simplified version of ExBi methodology. Difference of available data input objects are described within the openAPI documentation of NaeBi-Service. Objects varying in SuiBi compared to ExBi are indicated by

e.g. ExBi

In order to calculate applied slurry onto the field it is necessary to give information regarding slurry dilution (fieldSpreading.dilutionRatio) and amount of slurry applied per ha (fieldSpreading.quantity). If slurry is either produced by declared animalStock or imported via declared farmManureTrading.dispense and the described parameters for slurry application are not declared Slurry application on field will not be calculated

e.g. SuiBi

Inside SuiBi, the parameters slurry dilution (fieldSpreading.dilutionRatio) and amount of slurry applied per ha (fieldSpreading.quantity) are both set with default parameters. If slurry is either produced by declared animalStock or imported via declared farmManureTrading.dispense Slurry application on field is calculated automatically via fixed default parameters and does not require input of the described fields.

Difference between Planning Balance and Controlling Balance

There are two different endpoints for calculating a planning balance and a controlling balance. The calculation methodology is made up of nutrient production and a nutrient requirement calculation. The nutrient production is calculated from the animal excrement via the farmyard manure cascade according to the Agramon model, the supply and removal of manure and the nitrogen utilisation rate of the recycled, mineral and farmyard manure produced on the pasture or applied to the field. The nutrient requirement, which is calculated using the basic forage balance and information on the basic forage, arable and specialised areas, is compared with the amount produced.

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