Graze food store type

This represents the coefficient of the equation to convert Nitrogen (%) to Dry Matter Digestibility (DMD, %) in the form

This represents the intercept of the equation to convert Nitrogen (%) to Dry Matter Digestibility (DMD, %) in the form

The nitrogen content of the new pasture if not provided from an input file (forage).

This represents the amount in (Percent Nitrogen) lost each month. Note, this is an amount not a proportion or percentage. For example if the loss was 0.5% and there was currently 1.5% Nitrogen, there would be 1.0% Nitrogen the following month (1.5 - 0.5 = 1.0).

The minimum nitrogen content this pasture can decay to.

This represents the proportion of Dry Matter Digestibility (DMD) lost each month.

The minimum Dry Matter Digestibility (DMD, %) this pasture can decay to.

The monthly detachment rate, or rate at which pasture in the pool is lost. This relates to pools less than 12 months old. (see also Carryover detachment rate). Detached material is lost from the pasture store.

The monthly detachment rate of pools greater than 12 months old. Detached material is lost from the pasture store.

The IntakeTropicalQualityCoefficient parameter is used to reduce ruminant intake from grazing as a function of tropical pasture quality and any reduction in digestion for reasons such as high silica levels. For details see Potential intake pasture quality limiter.

The IntakeQualityCoefficient parameter is used to reduce ruminant intake from grazing as a function of pasture quality. For details see Potential intake pasture Biomass limiter.

Pasture biomass in place at the start of the simulation is often a critical requirement to ensure feed is available for grazing and the pasture pools are ready for the next pasture production. This parameter specifies the biomass present in this pasture at the start of the simulation. As the pasture does not have any information regarding the area until managed by a Manage crop or Manage pasture activity this value is provided as units pasture per unit area (as pasture is usually measured in kg and area in ha, this would be kg per ha). The pasture management activities will handle the calculation of initial pasture pools using the following parameters.

A number of additional parameters are required to determine the assignment of initial biomass to the various previous pasture pools and determine quality.

First month of seasonal growth

This parameter determines the first month of any seasonal pasture growth. For example, summer dominated pasture growth in northern Australia could start in November, while winter dominated growth could start in May. For no seasonality in pasture production, use January

month

Last month of seasonal growth

This parameter determines the last month of any seasonal pasture growth. For example, summer dominated pasture growth in northern Australia could cease in March. For no seasonality in pasture production, use December

month

Number of months for initial biomass

This parameter determines the number of months across which to spread the initial pasture production. This is usually the difference between FirstMonthOfGrowth and LastMonthOfGrowth, but may be set across multiple seasons (years) if decay rates are low

The GrazeFoodStorePool component is the actual store of pasture resource for each pool. A pool contains all the food parameters and tracks changing Nitrogen and Dry Matter Digestibility through time as well as the age (in months) of the pool. This is not visible to the user in the user interface tree and all requests are made to the parent Graze food store type which handles how much is taken from each pool based on ruminant parameters. Like the Animal food store types this component will update the requester’s (individual Ruminant) intake, percent Nitrogen and Dry Matter Digestibility when resources are supplied. You can access the pools for reporting using the Pool(index, usage) method of the Graze food store type where use age is a boolean (true/false) switch that determines whether age (true) or pool index is used for reporting. This is automatically handled by the recommended Pasture pools report.

When using the advanced grazing style with pasture production provided from a data-cube, a Land Condition Index (see Tracking land condition and pasture state) versus pasture utilisation Relationship is required below this Resource type. This requires a further Relationship running value component (named "LC" as a child component) to dynamically track the land condition index during the simulation based on pasture utilisation in each paddock. This value is then used to look-up the appropriate pasture production from the pasture input database.

When using the advanced grazing style with pasture production provided from a data-cube, a Grass Basal Area (see Tracking land condition and pasture state) versus pasture utilisation Relationship is required below this Resource type. This requires a further Relationship running value component (named "GBA" as a child component) to dynamically track the grass basal area during the simulation based on pasture utilisation in each paddock. This value is then used to look-up the appropriate pasture production from the pasture input database.

For full details see Tracking land condition and pasture state.