SnapPlus Help Version 19

SnapPlus Glossary of Terms

SnapPlus Glossary of Terms

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SnapPlus Glossary of Terms

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1st & 2nd yr legume credit

The N fertilizer value supplied by legumes to crops following in the first or second year.

2nd yr manure credits

The fertilizer value applied to manure in the second cropping season after application.

3rd yr manure credits

The fertilizer value applied to manure in the third cropping season after application.


On the field screen, checkbox that identifies fields that are actively part of the farming operation. Unchecking it removes the field from the purview of the cropping screen, SnapMaps, and reports, but does not delete it.

Adjusted UW recommendation

P2O5 and K2O recommended by University of Wisconsin for that crop and soil test, minus P2O5 and K2O banked since the last soil test.

Animal units

Unit of measure used to determine the total amount of single animal types or combination of animal types on a farm. For example, a 1,000 lb cow equals 1 animal unit, and a 1,400 lb cow equals 1.4 animal units.

Annual Total PI

The Phosphorus index for a specific cropping year.

Average Soil Loss

Average tons per acre per year (t/ac/yr) lost from a field for the specified rotation, calculated using RUSLE2.

Avg P Index

Rotation average P Index calculated by estimating the average annual runoff P delivery from a field to surface water (lb/ac/yr). The average P Index is a combination of soluble P and particulate P.


The P2O5 and K2O balances represent the difference between total applications and crop removal over the duration of the rotation. Positive balances indicate that soil P and K concentrations are likely to be increasing. Negative balances mean that soil concentrations may be decreasing over the rotation.

Below field slope to water (%)

The field slope percentage range for the route water flows from the edge of the field to perennial water (anything that holds or flows water year-round).


An acronym for Concentrated Animal Feeding Operation, which is defined as an operation with 1,000 animal units or more. The DNR may also designate a smaller-scale animal feeding operation as a CAFO if it has a pollutant discharge to navigable waters or contaminates a well.

Concentrated flow channel

Areas within fields or on field edges where water flow comes together in small channels or gullies.


Describes how a field is worked across a slope. The three options are none, on-contour, and strip cropping.  None is the default setting, and should be selected whenever a field is not consistently worked across the slope.  On contour should be selected when a field is consistently planted and tilled on the contour across the slope. Strip crop should be selected when contour strips have been installed and maintained on a field. For more information and guidance for establishing contour strips, see WI NRCS Conservation Practice Standard 330 Contour Farming or 585 Strip Cropping.

Daily log

Allows for the tracking of daily manure applications.  Must be used for DNR Form 3200-123A, which is a form required of CAFOs. Can also be used for recording fertilizer and lime applications, and for grazing records.

Data dump

Found on the Reports screen and allows the user to export annual cropping data or applications data for multiple years into Excel. This can be used to make customized reports with SnapPlus data.

Distance to perennial water

The distance in feet from the edge of the field to perennial water (anything that holds or flows water year-round). Perennial streams, ponds and lakes are shown on the Perennial Stream and Waterbodies layers in SnapMaps.

Field “T”

Stands for Tolerable soil loss (the amount the field can lose in tons/acre/year) as determined by soil type.

Filter Area

A grass strip within a field or an area on the edge of a field designed to capture sediment in runoff. All of the options assume there are no concentrated flow channels through the grass filters. None is the default setting for filter strips. Designed field edge is a grass filter strip designed to filter flow from the field.  In the soil loss calculations, it is represented by a 30 foot cool season grass filter strip. Designed in-field is when a grass buffer strip is established on the contour within the field . It is represented in the soil loss calculation by a 15 ft. cool season grass filter placed in the middle of the Field Slope Length. For more information, see WI NRCS Conservation Practice Standard 393 Filter strip or 332 Contour buffer strip.


Collection of fields used to narrow the focus for reports and SnapMaps, usually based on criteria you specify. Use Easy Group Builder or the Groups tab on the Fields screen For  example, you can create a group determined by cropping type, soil fertility, and others. A field can be in multiple groups. See also Subfarm.


Manure or fertilizer applied to the surface and mixed with the surface using tillage or infiltration methods within 1-72 hours after application.


Manure injected below the soil surface or incorporated by tillage within 1 hour of application.


An acronym for Maximum Return to Nitrogen, a calculation providing maximum economic returns based on the cost of N and an anticipated corn or wheat price. See MRTN Information for more information.

MRTN Price Ratio

Determined by dividing the cost of N ($/lb) by the price of corn ($/bu).  

MRTN Range Point

After determining the MRTN price ratio, a recommendation is given with a range.  The MRTN range point is the location within that range which should be the fields target N application based on a number of environmental and previous manure application factors, refer to UW Nitrogen Guidelines for corn for more information.

N restriction

If the field contains an N restricted soil, then the field has a high potential for leaching to groundwater and is limited in the amount of N that can be applied in the fall. For more information on restrictions, see the WI 590 Standard.


An acronym for Neutralizing Index, (NI = fineness factor of lime x purity factor of lime). The higher the NI the quicker the reaction in the soil.

Nutrient System

A set of fertilizers and applications that can be applied in a single operation to a field. See Nutrient System Editor.

Over/under adjusted UW rec

The total pounds per acre either over or under the recommendation; negative indicates under the recommendation, a positive number indicates over the recommendation.

Particulate PI

The portion of runoff P lost through soil erosion (a.k.a. sediment-bound P), reported on an annual basis.

Prior year extra

Carry-over or “banked” P2O5 and K2O that was applied in excess of the crop recommendation in a previous year. This carry-over is reset to zero with new soil tests.


The P2O5 and K2O removal show the expected crop removal across the rotation.

Restrictions (590 restrictions)

Nutrient application restrictions dictated  by the 590 standard including winter spreading, surface water quality management area (SWQMA), fall nitrogen application, set-backs from conduits to groundwater, and other restrictions.


The order and series of crops grown on a field. For example, a 6-year rotation might include 2 years of corn, 1 year of alfalfa seeding, and 3 years of alfalfa.

Rotation settings

The start date and duration of the field's rotation that is used to determine average soil loss and  the phosphorus index. The settings  also accounts for contouring or filter areas if those radio buttons are selected.


A sample is made up of separate 6-8 inch soil cores (minimum of 10) taken from a field and mixed to make a single composite sample.  For a field, one sample per five acres is needed to determine the average soil test for the field.


Refers to the time when applications are being made.  They do not necessarily follow the typical calendar.  Choose Fall for late summer and fall applications that are applied prior to a crop that will be harvested the following crop year.  Also select Fall for late summer or fall applications prior to cover crops that will not be harvested, as these nutrients will be returned to the soil and should be credited to the following harvested crop. Select Winter for applications that are planned for the time when the soil is likely to be frozen, usually December through March or mid-April, depending on location. Choose Spring for applications that are planned for after the soil has completely thawed and before mid-June. Select Summer for mid-June to August applications for hay crops or crops that will be harvested in that crop year, including crops that are seeded in the summer for late summer or fall harvest. See also Selecting the Season and Crop Year for Manure and Fertilizer.

Soil map symbol (critical)

The most erosion-sensitive soil that makes up at least 10% of the field. Used to calculate soil loss and the P Index.

Soil map symbol (predominant)

The soil that makes up the largest portion of the field. Used to determine fertilizer recommendations in SnapPlus.

Soil test

The average analysis for all of the soil samples taken on a specific date for the specific field.

Soluble PI

The portion of annual phosphorus loss that is attributed to phosphorus that is dissolved in runoff water, either from soil or fertilizer sources such as manure.

Source name

A unique name given to a particular manure or fertilizer used in a SnapPlus farm database.

Spread method

The different options for application of manure and fertilizer that can affect the nutrient value. Choices for manure are incorporated, unincorporated and injected. Choices for fertilizer are incorporated, unincorporated and subsurface.

Spreadable Acres

The number of acres that manure can be spread on for a given field. See Spreadable Acres for more information on how the program uses them.


A useful tool for organizing fields, which can be used to sort fields for reports and applications.  Fields can only belong to one subfarm. See also Group.


When fertilizer is applied below the soil surface, such as in-row placement.


An acronym for Surface Water Quality Management Area, which is defined as 1000 ft from a pond or lake, and 300 ft from a stream or river.


Manure applied to the surface or incorporated more than 72 hours after application and fertilizer that is broadcast and left on the surface.

UW Recommendation

University of Wisconsin nutrient recommendations for a specific crop based on soil analysis, crop yield and soil yield potential. Detailed information can be found in UWEX publication A2809, Nutrient application guidelines for field, vegetable, and fruit crops in Wisconsin.

WPDES permitted farm

An acronym for Wisconsin Pollutant Discharge Elimination System. Any livestock or poultry operation with 1,000 or more animal units is considered a concentrated animal feeding operation (CAFO) under current regulation and is required to apply for and operate under a DNR-issued water quality protection permit.