Management Operation Database Record Development

Introduction

In the Wind Erosion Prediction System (WEPS), changes in the "state" of the surface, soil, and biomass (residue and live vegetation) during a simulation are modeled, because they have a direct impact upon a site's susceptibility to wind erosion. Cultural practices applied during management of a site can significantly influence a site's "surface, soil, and biomass" state over time. It is an important variable because it is the primary factor that a land manager can most easily change in the field to affect a site's susceptibility to wind erosion. Therefore, WEPS simulates many management practices, which typically include operations like tillage, cultivation, planting, harvesting, irrigation, residue burning, etc.

WEPS can represent a wide range of typical management operations used on agricultural crop land. It does so by defining each operation as an ordered list of "processes", which represent physical actions like residue burial, soil loosening and mixing, etc., that occur when that operation is performed on the field. By simulating these physical processes, WEPS can reflect the changes made by an operation to a site's "surface, soil, and biomass" state.

The purpose of this guide is to describe the process of: a) developing accurate WEPS representations of management operations as correctly ordered lists of processes or actions; b) obtaining reasonable parameter values for the list of individual processes describing each management operation, based upon knowledge of that operation's characteristics; and c) providing a reference description for each of the physical "processes" simulated by WEPS.

Operation Database Records

WEPS management operation database records are stored in an XML file format with the extension .oprn for use by the WEPS interface. Supporting files, which define the database structure are part of the MCREW (Management/Crop Rotation Editor for WEPS) configuration files. New individual operation database records can be created in several ways: 1) using a text editor to edit the .oprn file (operation record) directly; 2) using MCREW to edit an existing operation record, via its "operation drill-down" feature, and saving it to a new name; or 3) using the WEPS crop/op database viewer/editor program. We will be focusing on the use of the WEPS crop/op database viewer/editor program here because it provides the best user environment for creating and editing WEPS management operation records. Note that for NRCS most parameter choices will not be editable by Field Office Users. NRCS will use a database manager to adjust and distribute new or revised database file.

Each operation record is simply an ordered list of "actions" or "processes" that represent the physical effects that a management operation is to perform. An example operation record for a springtooth harrow is shown in Figure 1.41.

Note in Figure 1.41 that the definition of the operation simply consists of a list of parameters that are grouped under an "operation", "group" or "process" name. An "operation" line, which is labeled with a code letter of "O", contains parameters that apply to the operation as a whole. For example, the direction and speed of travel are specified by the parameters "odirect" and "ospeed". Each operation will contain a single "operation" line in its definition. There are several types of valid "operation" lines defined for WEPS operations, each of which has a unique identification number. All the valid operation lines are listed and defined later.

The second line in Figure 1.41 is a "group" line. To explain the purpose of a "group" line, we must first define the "process" lines that follow. WEPS attempts to simulate the "physical effects" a management operation has on the soil, surface, and vegetation. Within WEPS, the individual, specific identified actions that represent an operation are simulated in the order specified in the management operation record. In this example, the springtooth harrow performs the following actions in the given order: 1) breaks surface crust if it exists; 2) creates a specified random roughness on the surface; 3) removes any ridges and dikes that may be present before to this tillage operation; 4) breaks down (crushes) soil aggregates, resulting in a new distribution of the aggregate sizes; 5) reduces the soil bulk density (loosens the soil); 6) does some mixing of the soil within the depth of tillage; and 7) kills any growing vegetation.

Therefore, each "process" line may contain one or more parameters required for WEPS to simulate the particular physical process or action represented by that line in the model. Some of these physical processes may require additional parameters needed by other, related processes. For example, the "Layer Mixing" and the "Soil Loosening" process lines represent the physical loosening and mixing of the soil by the springtooth. The parameter values "soilos" and "laymix" define the degree of mixing and loosening of soil that will occur. To properly simulate these physical actions, however we need the depth of tillage so that we know how deep the mixing and loosening of the soil will occur. That information is provided in the "group" line by the variable "gtdepth". Thus, the "shared" tillage depth parameter value required to simulate both the mixing and loosening actions is made available in one place, because it will have the same value for both the mixing and loosening actions being simulated. This is desirable because there is only one tillage depth parameter whose value needs to be changed if the tillage depth is altered for the operation.

So, in summary, each WEPS management operation will consist of a single "operation" line and one or more "process" lines, where each "process" line typically represents a single physical action or event that the operation does on the field. If specific "process" lines require additional "shared" parameters for WEPS to simulate the physical action they represent, then the appropriate "group" line containing those parameters will be specified before those "process" lines. Because WEPS simulates the physical actions represented by the "process" lines in the order they are specified in the management operation record, the order of the listed "process" lines is important and must be correct for WEPS to properly simulate the operation's total effect on the field.

Operation Database Structure Files and Definitions

The parameter descriptions provide the keys to enable the user to know which parameter is being edited. A current reference table is easily viewed by opening the operation_defn.xml file in the mcrew_cfg directory using a web browser, as seen in Figure 1.42.

The parameters defined in this section are described by a Parameter Prompt, the text that appears in MCREW; Parameter Unit, the named unit that the WEPS science model expects the parameter value to be in; Conversion Factor, the combination of multiplier and additive terms that will convert the parameter value from the default Parameter Units; Param Units (SI), to the specified Alternate Units, Alternate Units (English), the named unit that values will be displayed in, given the selection of units in the WEPS configuration; and Parameter Choices, a list of choices displayed when the parameter is defined as a discrete set of values, often integer flags. The parameters are grouped according to the specific "process", "group", or "operation" line they pertain to.

Management Operation Parameter Definitions

O 00: Initialization

The "Initialization" operation line represents a special type of operation. It is intended to be used when one needs to "initialize" a WEPS simulation run in a special manner. Therefore, any operation defined with an "Initialization" operation line will only be executed once, during the initialization cycle, and will not be repeated like other normal operations. This type of operation will usually only be created and used by researchers or for special WEPS uses.

Parameter Prompt:	Initialization Operation Notes

The "Initialization" operation line contains only this one parameter. It allows the user to document the specific purpose of the operation, special considerations specific to its use, creation date, author, any subsequent changes, etc.

O 01: Direction and Speed

In many management events, like tillage operations, the actual speed of the operation and/or the direction in which the operation is performed on the field can influence the degree to which it impacts the physical state of the soil, surface, and vegetation. These types of management events will be defined with the "Direction and Speed" operation line.

Parameter Prompt:	Speed

Actual speed at which the operation is performed.

Parameter Unit:	m/s

Conversion factor:	mph = 2.237 * (m/s)

Alternate units:	mph

Parameter Prompt:	Direction from North

This parameter defines the principle direction, relative to north, in which the operation is performed. Zero (0.0) degrees represents a north/south direction. 90.0 degrees represents an east/west direction. This parameter defines the predominant direction of tillage ridges and/or planted rows. It is important because oriented surface roughness and row direction relative to wind direction affect the susceptibility of the field to wind erosion.

Parameter Unit: degrees

Parameter Prompt:	Standard Speed

Speed at which some of the physical processes, like residue burial efficiency, have coefficients specified. In WEPS, many of these coefficients are then adjusted internally based upon actual travel speed, as well as other parameters.

Parameter Unit:	m/s

Conversion factor:	mph = 2.237 * (m/s)

Alternate units:	mph

Parameter Prompt:	Minimum Speed

Minimum speed at which the operation would typically be performed. This speed value is used to determine the lower limit at which WEPS will adjust certain process-
specific parameters that are influenced by travel speed.

Parameter Unit:	m/s

Conversion factor:	mph = 2.237 * (m/s)

Alternate units:	mph

Parameter Prompt:	Maximum Speed

Maximum speed at which the operation would typically be performed. This speed value is used to determine the upper limit at which WEPS will adjust certain process-
specific parameters that are influenced by travel speed.

Parameter Unit:	m/s

Conversion factor:	mph = 2.237 * (m/s)

Alternate units:	mph

Parameter Prompt:	Tillage Operation Notes

This parameter allows the user to document the specific purpose of the operation, special considerations specific to its use, creation date, author, any subsequent changes, etc.

O 02: Others

Management events that are not influenced by speed of operation or direction of travel. Examples would be most grain-harvest, herbicide-spraying, baling, burning, and irrigation operations.

Parameter Prompt:	Other Operation Notes

This parameter allows the user to document the specific purpose of the operation, special considerations specific to its use, creation date, author, any subsequent changes, etc.

G 01: Tillage

Many tillage operations perform several physical processes as they modify the soil and surface condition (e.g., loosening the soil, mixing soil properties within the tillage zone, burial of residue, etc.). All of these physical processes require some information that is common among them. These "shared" parameter values, like tillage depth, surface area disturbed, etc., have been grouped together into a single "group" line so that they don't have to be specified repeatedly as parameters for each individual process that needs them. This allows one to conveniently make a single change to a "shared" parameter listed in a group line and have it impact all the succeeding processes that require it. But it also requires one to ensure that any process line that requires a "shared" parameter has the appropriate "group" line specified before the process line in the definition file of that operation.

Often, a tillage operation may contain multiple tillage tool components on a single implement (e.g., disk gang, followed by a row of chisel shanks) or consist of a several individual implements one behind the other (e.g. a springtooth harrow with a straight tine drag harrow behind it). These types of tillage operations/implements can be represented as a single operation in WEPS by specifying the physical processes each tillage tool component performs on the soil/surface/vegetation. Often, this is done by specifying a "Tillage" group line, followed by the appropriate "process" lines to represent the tillage/residue burial effects of the individual tillage tool components. Thus, multiple tillage "group" lines, followed immediately by several "process" lines, will be used to represent multi-tool and multi-
implement tillage operations in WEPS.

Parameter Prompt:	Actual Depth

Actual tillage depth of the implement or tillage tool component represented.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Intensity

Tillage intensity of the implement or tillage tool component represented. It can have a value from 0.0 to 1.0, where zero represents no soil disturbance and 1.0 would represent maximum soil disturbance. This parameter value impacts the soil layer "mixing" process simulated within WEPS, as well as soil loosening. An example of a tool with a high tillage intensity would be a rotary tiller.

Parameter Unit:	fraction

Parameter Prompt:	Area Affected

The fractional surface area affected by the tillage processes. It can have a value from 0.0 to 1.0, where zero would represent no surface area disturbed. A value of 1.0 would mean that the tillage processes occurred across the entire width of the implement. A value between 0.0 and 1.0 would mean that only a fraction of the surface and the soil below would be disturbed, (e.g., a row crop cultivator may only till the soil between the plant rows).

Parameter Unit:	fraction

Parameter Prompt:	Standard Depth

Tillage depth at which some of the physical processes, like residue burial efficiency, have coefficients specified. In WEPS, many of these coefficients are then internally adjusted based upon actual tillage depth, as well as other parameters.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Minimum Depth

Minimum tillage depth at which the operation would typically be performed. This depth value is used to determine the lower limit at which WEPS will adjust certain process-specific parameters that are influenced by tillage depth.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Maximum Depth

Maximum tillage depth at which the operation would typically be performed. This depth value is used to determine the upper limit at which WEPS will adjust certain process specific parameters which are influenced by tillage depth.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

G 02: Biomass Manipulation

The "Biomass Manipulation" group contains a "shared" parameter that is required by many WEPS processes that simulate the manipulation of biomass (e.g., the removal of biomass, flattening of standing residue, etc.). This "group" line is commonly used for operations that do not affect (till) the soil, where the "shared" parameters dealing with tillage depth in the "Tillage" group are not required. Examples of operations that would use this group line are harvesting and spraying operations.

Parameter Prompt:	Area Affected

The fractional surface area affected by the tillage processes. It can have a value from 0.0 to 1.0, where zero would represent no surface area disturbed. A value of 1.0 would mean that the biomass manipulation processes occurred across the entire width of the implement. A value between 0.0 and 1.0 would mean that only a fraction of the surface and biomass would be affected (e.g., a grain harvesting operation in which 1/3 of the crop was to be left in the field for wildlife purposes or in which the implement's wheel tracks flattened a fraction of the standing residue during the operation).

Parameter Unit:	fraction

G 03: Crop Name

The "Crop Name" group consists of a single parameter, the name of a crop being planted or transplanted. It is required by the planting/seeding and transplanting processes.

Parameter Prompt:	Crop Name

This parameter specifies the name of the crop being planted/seeded or transplanted.

G 04: Add Material to Field

The "Add Material to Field" group consists of a single parameter, the name of the residue type being applied. It is required by the "Add Residue" and "Set Residue" processes.

Parameter Prompt:	Material Name

This parameter specifies the name of the type of residue added to the field.

P 01: Break Crust

If this process is specified, it means that the operation will physically remove any crust on the soil surface. No process-level parameters are required for the simulation of this effect in WEPS. It does require a shared, group-level parameter that specifies the fraction of the surface area to which this effect applies.

P 02: Random Roughness

Parameter Prompt:	Random Roughness Flag

Some tillage operations will create a specific random surface roughness, regardless of the pre-existing soil surface/biomass conditions, and others are highly dependent upon the soil type, pre-tillage surface cloddiness, and quantity of buried residue present. To allow for these differences, a "Random Roughness Flag" is used to specify how WEPS should treat a specific tillage tool.

Parameter Choices:	0 - Always use specified random roughness value

1 - Allow WEPS to auto-adjust random roughness value

Parameter Prompt:	Nominal Random Roughness

If the "Random Roughness Flag" is set to zero (0), then this value is the Allmaras random roughness value that the soil surface will have after using this tillage tool.

If the "Random Roughness Flag" is set to one (1), then this is to be the typical Allmaras random roughness value expected on a silt loam soil with lots of buried residue present. Internally, WEPS will use the "shared" group parameter values of "tillage intensity", soil type, and residue quantity to determine the actual surface roughness created by the tillage tool. In general, a high tillage intensity value will mean that the "Nominal Random Roughness" will not be affected much by the pre-
tillage surface roughness. A low tillage intensity value would affect the final random roughness. In general, a sandier soil will result in a lower random roughness value, and a soil with more clay will create a surface with a higher random roughness value. Because most field conditions are performed with less residue than specified for the "Nominal Random Roughness" value, the resulting surface roughness will be less than the specified value.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

P 05: Ridges and Dikes

Parameter Prompt:	Ridge Flag

Tillage operations will either: a) leave existing ridges alone; b) create a specified ridged and/or diked surface, regardless of pre-existing surface conditions; or c) create a specific ridged and/or diked surface based upon tillage depth. The "Ridge Flag" specifies which of these situations should represent how WEPS should treat a specific tillage tool.

Parameter Choices:	0 - Pre-existing ridges/dikes left unchanged

1 - Ridges/dikes set to specified values

2 - Ridges/dikes set, based upon tillage depth

Parameter Prompt:	Ridge Height

Ridge height is measured from the top of the ridge to the bottom of the furrow.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Ridge Spacing

Ridge spacing is measured from ridge top to ridge top across the furrow.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Ridge Top Width

Ridge width is measured across the top of the ridge.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Dike Height

Dike height is measured from the top of the dike to the bottom of the furrow.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Dike Spacing

Dike spacing is measured from dike top to dike top down the furrow.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

P 11: Aggregate Crushing

Parameter Prompt:	Aggregate Size Distribution Factor

Parameter Unit:	unitless

Parameter Prompt:	Crushing Intensity Factor

Parameter Unit:	unitless

P 12: Soil Loosening

Parameter Prompt:	Soil Loosening Factor

Specifies degree to which air is added to the soil layers within the tillage zone. A minimum value of zero (0.0) means no change in soil layer bulk density occurs. A maximum value of 1.0 means the soil layers reach their "loosest" state (i.e., the lowest bulk density possible for the soil type, based upon the pre-tilled bulk density value).

Parameter Unit:	fraction

P 13: Soil Layer Mixing

Parameter Prompt:	Layer Mixing Factor

Specifies degree of mixing among soil layer properties. A minimum value of zero (0.0) means no mixing occurs, and a maximum value of 1.0 means full mixing occurs, (i.e., all layers within the tillage zone become homogeneous).

Parameter Unit:	fraction

P 14: Soil Layer Inversion

Specifies that the current tillage tool inverts the soil layers within the specified tillage zone.

This process line has no parameter values.

P 24: Flatten Standing Biomass

This process specifies the degree to which standing crops and/or residue are flattened. There are "flattening coefficients" specified for each type of "residue", on the basis of its "toughness/size". The five types of residue classes are:

fragile	- Residue that is easily broken down (e.g., soybean residue)

moderately tough	- Similar to size and toughness of wheat residue

non-fragile/large	- Similar to size and toughness of corn residue

woody	- Similar to size and toughness of woody brush residue

small stones/gravel	- Non-decomposing material

Parameter Prompt:	Flatten Biomass Flag

This parameter specifies which type of biomass is flattened, the "growing crop" and/or the standing crop residue remaining after previous crop harvests.

Parameter Choices:	0 - Flatten crop and residue

1 - Flatten crop only

14 - Flatten residue only

Parameter Prompt:	Mass Flattened (fragile residue)

Fraction of standing crop and/or residue flattened, if considered "fragile residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Flattened (moderately tough residue)

Fraction of standing crop and/or residue flattened, if considered "moderately tough residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Flattened ( non-fragile/large residue)

Fraction of standing crop and/or residue flattened, if considered "non-fragile/large residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Flattened (woody residue)

Fraction of standing crop and/or residue flattened, if considered "woody residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Flattened (small stones/gravel residue)

Fraction of standing crop and/or residue flattened, if considered "small stones/gravel residue". Tire traffic areas should be included in this fraction.

Parameter Unit:	fraction

P 25: Bury Flat Biomass

This process specifies distribution and the degree to which crops and/or residue are buried. There are "burial coefficients" specified for each type of "residue", on the basis of its "toughness/size". The five types of residue classes are specified under "Flatten Standing Biomass". The burial distribution pattern by depth is specified based upon the "Bury Biomass Flag" values. The five types of burial distribution patterns are:

Uniform	- Biomass is buried uniformly by depth

Mixing and inversion	- Biomass is inverted and mixed during burial

Mixing	- More biomass is buried near the soil surface

Inversion	- Biomass buried at bottom of tillage zone

Lifting, fracturing	- Biomass buried similar to a chisel plow

Parameter Prompt:	Bury Biomass Flag

This parameter specifies how residue is buried into the tillage zone.

Parameter Choices:	0 - Uniform burial distribution

1 - Mixing and inversion burial distribution

2 - Mixing burial distribution

3 - Inversion burial distribution

4 - Lifting/fracturing burial distribution

Parameter Prompt:	Mass Buried (fragile residue)

Fraction of above ground crop and/or residue buried, if considered "fragile residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Buried (moderately tough residue)

Fraction of above ground crop and/or residue buried, if considered "moderately tough residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Buried ( non-fragile/large residue)

Fraction of above ground crop and/or residue buried, if considered "non-fragile/large residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Buried (woody residue)

Fraction of above ground crop and/or residue buried, if considered "woody residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Buried (small stones/gravel residue)

Fraction of above ground crop and/or residue buried, if considered "small stones/gravel residue".

Parameter Unit:	fraction

P 26: Resurface Buried Biomass

This process specifies the degree to which buried residue are brought back to the surface. There are "re-surfacing coefficients" specified for each type of "residue", on the basis of its "toughness/size". The five types of residue classes are specified under "Flatten Standing Biomass".

Parameter Prompt:	Mass Resurfaced (fragile residue)

Fraction of below-ground crop and/or residue resurfaced, if considered "fragile residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Resurfaced (moderately tough residue)

Fraction of below ground crop and/or residue resurfaced, if considered "moderately tough residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Resurfaced ( non-fragile/large residue)

Fraction of below ground crop and/or residue resurfaced if, considered "non-
fragile/large residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Resurfaced (woody residue)

Fraction of below ground crop and/or residue resurfaced, if considered "woody residue".

Parameter Unit:	fraction

Parameter Prompt:	Mass Resurfaced (small stones/gravel residue)

Fraction of below ground crop and/or residue resurfaced, if considered "small stones/gravel residue".

Parameter Unit:	fraction

P 31: Kill or Defoliate Growing Crop

This process determines whether a growing crop is defoliated or killed, based upon the type of crop (perennial or annual).

Parameter Prompt:	Kill/Defoliate Flag

This parameter specifies how different crop types are treated (e.g., killed or defoliated).

Parameter Choices:	1 - Annual crop killed, perennial crop regrows

2 - All crop types are killed

3 - Crop defoliated

P 32: Cut/Remove Biomass to Height

This process cuts the specified standing biomass (crop and residue if present) to the specified height. This process is also a harvest process if components of the cut material are removed from the field as specified by the removal parameter values. Based upon the "Cut Biomass Flag" setting, the cut height is measured from the ground up or from the top of the crop down.

Parameter Prompt:	Cut Biomass Flag

This parameter specifies how the cut height is determined.

Parameter Choices:	0 - Cut Value = Height of standing stubble remaining

1 - Cut Value = Length of standing plant stalks removed

Parameter Prompt:	Cut Value

Either the cutting height or the length (height) of crop removed, based upon the "Cut Biomass Flag" value.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Cut Yield Removed

Mass fraction of crop yield removed during the "Cut/Remove Biomass to Height" process.

Parameter Unit:	fraction

Parameter Prompt:	Cut Plant Removed

Mass fraction of "cut" crop biomass removed during the "Cut/Remove Biomass to Height" process.

Parameter Unit:	fraction

Parameter Prompt:	Cut Standing Residue Removed

Mass fraction of "cut" standing residue removed during the "Cut/Remove Biomass to Height" process.

Parameter Unit:	fraction

P 33: Cut/Remove Biomass by Fraction

This process cuts the specified standing biomass (crop and residue if present) to a fraction of the crop height. This process is also a harvest process if components of the cut material are removed from the field as specified by the removal parameter values.

Parameter Prompt:	Plant Height Removed

Fraction of crop (and residue if present) height removed during the "Cut/Remove Biomass by Fraction" process.

Parameter Unit:	fraction

Parameter Prompt:	Cut Yield Removed

Mass Fraction of crop yield removed during the "Cut/Remove Biomass by Fraction" process.

Parameter Unit:	fraction

Parameter Prompt:	Cut Plant Removed

Mass fraction of "cut" crop biomass removed during the "Cut/Remove Biomass by Fraction" process.

Parameter Unit:	fraction

Parameter Prompt:	Cut Standing Residue Removed

Mass fraction of "cut" standing residue removed during the "Cut/Remove Biomass to Height" process.

Parameter Unit:	fraction

P 34: Change Standing Biomass Fall Rate

This process allows an operation to modify the fall rate of decay for standing residue stalks. The purpose is to simulate the effects of undercutting the supporting roots, which decreases the ability of residue stalks to remain standing over time.

Parameter Prompt:	Select Biomass Pool Type

This parameter specifies how the cut height is determined.

Parameter Choices:	1 - Crop

2 - Temporary

3 - Crop and Temporary

4 - Residue

5 - Crop and Residue

6 - Temporary and Residue

7 - Crop, Temporary and Residue

Parameter Prompt:	Standing Biomass Fall Rate Multiplier (fragile residue)

Multiplier value to increase or decrease the fall rate value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Rate Multiplier (moderately tough residue)

Multiplier value to increase or decrease the fall rate value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Rate Multiplier (non-fragile/large residue)

Multiplier value to increase or decrease the fall rate value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Rate Multiplier (woody residue)

Multiplier value to increase or decrease the fall rate value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Rate Multiplier (small stones/gravel residue)

Multiplier value to increase or decrease the fall rate value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Threshold Multiplier (fragile residue)

Multiplier value to increase or decrease the threshold fall value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Threshold Multiplier (moderately tough residue)

Multiplier value to increase or decrease the threshold fall value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Threshold Multiplier (non-fragile/tough residue)

Multiplier value to increase or decrease the threshold fall value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Threshold Multiplier (woody residue)

Multiplier value to increase or decrease the threshold fall value for the specified type of residue.

Parameter Unit:	multiplier

Parameter Prompt:	Standing Biomass Fall Threshold Multiplier (small stones/gravel residue)

Multiplier value to increase or decrease the threshold fall value for the specified type of residue.

Parameter Unit:	multiplier

P 37: Thin Biomass to Population

This process reduces the crop plant population to the specified value. This process is also a harvest process if components of the "thinned" plants are removed from the field as specified by the removal parameter values.

Parameter Prompt:	Thinning Value

Resulting plant population desired.

Parameter Unit:	#/m^2

Conversion factor:	#/ft^2 = 0.0929 * (#/m^2)

Alternate units:	#/ft^2

Parameter Prompt:	Thinned Yield Removed

Mass fraction of "thinned" crop yield removed during the "Thin Biomass to Population" process.

Parameter Unit:	fraction

Parameter Prompt:	Thinned Plant Removed

Mass fraction of "thinned" crop plants removed during the "Thin Biomass to Population" process.

Parameter Unit:	fraction

Parameter Prompt:	Thinned Standing Residue Removed

Mass fraction of "thinned" standing residue removed during the "Thin Biomass to Population" process.

Parameter Unit:	fraction

P 38: Thin Biomass by Fraction

This process reduces the crop plant population by the specified value. This process is also a harvest process if components of the "thinned" plants are removed from the field as specified by the removal parameter values.

Parameter Prompt:	Thinning Value

Reduction factor to reach desired population.

Parameter Unit:	fraction

Parameter Prompt:	Thinned Yield Removed

Mass fraction of "thinned" crop yield removed during the "Thin Biomass by Fraction" process.

Parameter Unit:	fraction

Parameter Prompt:	Thinned Plant Removed

Mass fraction of "thinned" crop plants removed during the "Thin Biomass by Fraction" process.

Parameter Unit:	fraction

Parameter Prompt:	Thinned Standing Residue Removed

Mass fraction of "thinned" standing residue removed during the "Thin Biomass by Fraction" process.

Parameter Unit:	fraction

P 40: End Crop Biomass Manipulation

This process is required after all "crop" related biomass manipulation processes have been completed, for WEPS to correctly account for changes in vegetation pools within the simulation. There are no parameters associated with this process line.

P 50: Set Crop Residue Amounts

Parameter Prompt:	Number of Standing Residue Stems

Desired residue standing stem population.

Parameter Unit:	#/m^2

Conversion factor:	#/ft^2 = 0.0929 * (#/m^2)

Alternate units:	#/ft^2

Parameter Prompt:	Standing Residue Height

Desired standing residue height.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Standing Residue Mass

Desired standing residue mass.

Parameter Unit:	kg/m^2

Conversion factor:	lb/acre = 8921.8 * (kg/m^2)

Alternate units:	lb/acre

Parameter Prompt:	Flat Surface Residue Mass

Desired flat residue mass.

Parameter Unit:	kg/m^2

Conversion factor:	lb/acre = 8921.8 * (kg/m^2)

Alternate units:	lb/acre

Parameter Prompt:	Residue Size/toughness Class

This flag specifies the "class" of residue on the basis of its relative size and toughness.

Parameter Choices:	1-Fragile, very small residue (e.g., soybeans)

2-Moderately tough, short residue (e.g., wheat)

3-Non fragile, medium residue (e.g., corn)

4-Woody, large residue

5-Gravel, rock

Parameter Prompt:	Buried Residue Mass

Desired buried residue mass (not roots).

Parameter Unit:	kg/m^2

Conversion factor:	lb/acre = 8921.8 * (kg/m^2)

Alternate units:	lb/acre

Parameter Prompt:	Buried Residue Depth

Desired buried residue depth.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Root Residue Mass

Desired root residue mass.

Parameter Unit:	kg/m^2

Conversion factor:	lb/acre = 8921.8 * (kg/m^2)

Alternate units:	lb/acre

Parameter Prompt:	Root Residue Depth

Desired root residue depth.

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Decomposition Rate for Standing Stalks

The rate at which standing stalks decompose under optimum conditions. Example: a decomposition rate of 0.02 kg kg-1 day-1 means a 2% standing stalk mass loss per day if moisture and temperature conditions are optimum for decomposition on this day. If conditions are not optimum, the rate is reduced. Leaves, if any are present, decompose at 3 times the rate of stalks, and reproductive material, if any is present, decomposes at 1.5 times the rate of stalks.

Parameter Unit:	kg kg-1 day-1

Parameter Prompt:	Decomposition Rate for Surface (flat) Stalks

The decomposition rate of stalks that have fallen to a flattened (horizontal) position on the soil surface. See comments for standing stalks.

Parameter Unit:	kg kg-1 day-1

Parameter Prompt:	Decomposition Rate for Buried Stalks

The decomposition rate of stalks that have been buried below the soil surface by tillage. See comments for standing stalks.

Parameter Unit:	kg kg-1 day-1

Parameter Prompt:	Decomposition Rate for Roots

See comments for standing stalks.

Parameter Unit:	kg kg-1 day-1

Parameter Prompt:	Fall Rate for Standing Stalks

The rate at which standing stalks fall to a flattened (horizontal) position on the soil surface. Only after a threshold has been reached, stalks will begin to fall at this rate. Example: a fall rate of 0.12 day-1 means a 12% of the total number of standing stalks fall down per day if moisture and temperature conditions are optimum on this day. If conditions are not optimum, the fall rate is reduced.

Parameter Unit:	day-1

Parameter Prompt:	Average Stalk Diameter

Parameter Unit:	m

Conversion factor:	inches = 39.3696 * (m)

Alternate units:	inches

Parameter Prompt:	Decomposition Days After Which Stalks Begin to Fall

Only after this threshold has been reached, stalks will begin to fall at the rate previously discussed. Example: a threshold of 20 decomposition days means that standing stalks only begin to fall after 20 days after harvest if moisture and temperature conditions are optimum, during these 20 days. If conditions are not optimum the number of days increases.

Parameter Unit:	day

Parameter Prompt:	Mass to Cover Factor

Soil cover from flat residue mass is predicted by:

where Cf is flat residue cover (m2 m-2), b is mass-to-cover factor (m2 kg-1), and Mf is flat residue mass (kg m-2) (Figure 1.40, 43).

Parameter Unit:	m2 kg-1

Conversion factor:	value * 0.00011209

Alternate units:	acres lb-1

Parameter Prompt: Residue Evaporation Suppression Multiplier Coefficient a

Parameter Unit:	eratio = resevapa(kg/m2)**resevapb

Parameter Choices:

Parameter Prompt: Residue Evaporation Suppression Multiplier Coefficient b

Parameter Unit: eratio = resevapa(kg/m2)**resevapb

P 51: Seeding Configuration

Parameter Prompt:	Type of Planting

Specifies how the crop is being planted.

Parameter Choices:	0-Broadcast Planting

2-Use Implement Ridge Spacing

3-Use Specified Row Spacing

Parameter Prompt:	Crop Row Spacing

Parameter Unit:	mm

Conversion factor:	inches = 0.03937 * (mm)

Alternate units:	inches

Parameter Prompt:	Seed Placement (ridge/furrow)

Specifies where seed is to be placed when planting in rows.

Parameter Choices:	0-Seed row placed in bottom of furrow.

2-Seed row placed on ridge top.

Parameter Prompt:	Plant Population

Parameter Unit:	#/m^2

Conversion factor:	#/acre = 4046.7 * (#/m^2)

Alternate units:	#/acre

Parameter Prompt:	Maximum number of Tillers (stems) per Plant

Parameter Unit:	#/plant

NOTE: All remaining process 51 parameters consist of the "crop" database record parameters. They are fully defined in the crop "how to" guide. One normally would not need to deal with those parameters when defining/modifying an operation record, so they are not individually listed here.

P 61: Remove Plant/Residue Material

Parameter Prompt:	Select Plant/residue Material

This flag specifies the "location" of the biomass to be removed.

Parameter Choices:	1-Standing with Roots

2-Flat

3-Standing with Roots and Flat

4-Buried

5-Standing with Roots and Buried

6-Flat and Buried

7-Standing with Roots, Flat and Buried

Parameter Prompt:	Select Plant/residue Material

This flag specifies the biomass pool type(s) to be removed.

Parameter Choices:	1-Crop

2-Temporary

3-Crop and Temporary

4-Residue

5-Crop and Residue

6-Temporary and Residue

7-Crop, Temporary and Residue

Parameter Prompt:	Grain (fruit) Removed

Parameter Unit:	fraction

Parameter Prompt:	Leaf Removed

Parameter Unit:	fraction

Parameter Prompt:	Stem Removed

Parameter Unit:	fraction

Parameter Prompt:	Storage Root Removed

Parameter Unit:	fraction

Parameter Prompt:	Fibrous Roots Removed

Parameter Unit:	fraction

P 71: Irrigation

This process simulates the application of water.

Parameter Prompt:	Irrigation Application Method

This flag specifies the type of irrigation method.

Parameter Choices:	1-Sprinkler

2-Other

Parameter Prompt:	Depth of Water Applied

Parameter Unit:	mm

Conversion factor:	inches = 0.3937 * (mm)

Alternate units:	inches