The Field Restrictions dialog box is used to record the presence of field features which restrict nutrient applications according to the Wisconsin Nutrient Management 590. This dialog box can be accessed from the field screen, nutrient application planning screen and the cropping screen. For a detailed description of the top portion of the screen, see Understanding Fall Nitrogen Restrictions, below. For the bottom portion, see Understanding Field Restrictions.
Note that some of the field restrictions changed after crop year 2017 due to updates in the 590 standard. This description is for the restrictions currently implemented in SnapPlus.
Additional Field Restrictions for WPDES permitted farms:
If WPDES Permitted Farm is checked, an additional check box is added labeled CAFO SWQMA and the label Drinking water well within 50 ft of field edge is changed to within 100 ft of field edge.
WPDES permitted farms have a display for CAFO Manure Restrictions R and W soils.
There is an option to acknowledge use of proper techniques for W soil manure applications, which will turn off "manure prohibited on soils with less than 24 inches to the water table" Compliance messages in the Compliance Check Report and the flags on the Cropping tab. Proper techniques means field verification that the water table is below 24 inches at the time of application.
If depth to bedrock has been mapped for this field with all the areas with bedrock within 24 inches from the surface drawn in as Nutrient prohibited areas in SnapMaps, then checking the box next to this statement will turn off "manure prohibited on soils with less than 24 inches of soil over bedrock" Compliance messages in the Compliance Check Report and on the flags on the Cropping screen.
Field restriction features box for 590 standard field
FIeld restriction features box for WPDES-permitted field
Soil type for N restrictions: If the dominant critical soil and the predominant soil for this field are not soils with high leaching potential but the 590 restrictions maps show another soil or soils with high leaching potential in the field, pick one of those soils from the dropdown list in this cell, use Unlisted if your map shows a N restricted soil that is not in the list. If the dominant critical soil has an N restriction, the code will appear in the box.
Why do some fields have specific management requirements due to high N-leaching potential?
These fields have soils that are believed to be hazardous for fall N applications because of the risk of the nitrate form of N leaching to groundwater, leading to nitrate contamination of drinking water. These soils fit into at least one of the following categories:
•Highly permeable, allowing water to flow downward very quickly, or
•Less than 20 inches to bedrock, or
•Less than 12 inches to the water table
Code N restriction Definitions:
Definition of symbols:
P - High permeability N restricted soils
R - N restricted soils with less than 20 inches to bedrock
W - N restricted soils with less than 12 inches to apparent water table
+ - This map unit may have any of the N restrictive features, however an on-site investigation is needed to identify which restrictions may actually be present.
Less than 5 ft to bedrock: Fall commercial fertilizer nitrogen is restricted in these areas due to extreme vulnerability to groundwater contamination.
See Avoiding excess spring, summer and fall N applications on soils with a high nitrate leaching potential for more information on how to manage N applications on fields with these restrictions.
Understanding CAFO Manure Restrictions
NR 243.14(2)(b)(7) requires that CAFO manure or processed wastewater may NOT be applied on areas of the field with depth to groundwater or bedrock of less than 24 inches.
CAFO W & R Code definitions:
Definition of symbols:
R: Soil may have bedrock within 24 inches of soil surface.
W: Soil may have water table within 24 inches of soil surface.
+ - This map unit may have both of the manure prohibition features, however an on-site investigation is needed to identify which restrictions may actually be present.
Acknowledge use of proper techniques for W soil manure applications: The 'W' soils depth to groundwater may vary seasonally. By checking this box, the planner indicates that water table depth will always be checked at the time of manure application to ensure it is deeper than 24 inches across the field.
Field drains to 303 (d) or outstanding/exceptional waters: The P2O5 Balance on these fields should be zero or negative when soil test P is optimum or greater so that soil test P values will not increase (NR243.14 (5)).
Field restrictions are checked automatically when they are imported from SnapMap Restrictions. If you are entering field data by hand, you will need to check the appropriate restrictions.
Field in 590 SWQMA: SWQMA stands for Surface Water Quality Management Area. This should be checked if any part of the field is within 300 feet of and drains into a perennial stream or river or is within a 1000 feet of and drains into a lake or pond. Applications of manure within the SWQMA are prohibited if the soil is frozen and during the rest of the year conservation practices must be in place to to reduce the runoff potential if applications are made. If 0-300 is selected for Distance to Perennial Water (ft), this will be selected automatically.
Drinking water well or conduit to groundwater within 50 (100) ft of field edge: Nutrient applications are not allowed within 50 feet of a drinking water well or other types of direct conduits to groundwater (except corn starter and manure deposited by grazing animals). Permitted farms are not allowed to apply manure within 100 feet of conduits to groundwater.
Local prohibitions for winter applications: This indicates that there is a county prohibition on winter spreading on some part of this field. Although local prohibition areas show in SnapMaps, in v.17 this box needs to be checked by hand as the local prohibitions are not downloaded to the SnapMaps tab on the desktop.
Slope restriction for winter applications: This will be checked if any area of the field has a soil map unit with a default slope greater than 6%. For 590 planning, winter applications on these slopes require a) documentation that no more-suitable fields are available for winter spreading and b) use of two of the conservation practices described below under "Concentrated flow channel."
Concentrated flow channel: Check this box if there are concentrated flow channels within the field. According to the 590 code, applications of manure to fields with concentrated flow channels require using two of the following strategies:
1.Contour buffer strips or contour strip cropping
2.Leave all crop residue and no fall tillage
3.Apply manure in intermittent strips on no more than 50% of field
4.Apply manure on no more than 25% of the field waiting a minimum of 14 days between applications
5.Reduce manure app. rate to 3,500 gal. or 30 lbs P2O5 whichever is less
6.No manure application within 200 feet of a ll concentrated flow channels
7.Fall tillage is on the contour and slopes are lower than 6%.
February/March prohibition on liquid manure: No surface applications of liquid manure are allowed during February and March where Silurian dolomite is within 60 inches of the soil surface or where DNR Well Compensation funds provided replacement water supplies for wells contaminated with livestock manure .
Field in CAFO SWQMA: Surface Water Quality Management Areas for WPDES permitted farms extend beyond those designated by the 590 Standard and include areas within 300 feet of all conduits to navigable waters and are therefore not limited to areas adjacent to perennial waters. The CAFO SWQMA boundaries for both perennial and intermittent streams are mapped in SnapMaps. In addition, when the checkbox for "conduit to navigable water" is checked for new concentrated flow channels drawn in SnapMaps, the software will outline SWQMA boundaries for the new flow channel. If Field in 590 SWQMA is checked, the Field in CAFO SWQMA box will automatically be checked.
Public Well within 100ft: No manure applications are allowed within 100 ft (except treated manure and grazing). If this is checked, the conduits to groundwater within 300 ft of field will get checked automatically as well.
Municipal well within 1000ft: No manure allowed within 1000ft (except treated manure and grazing), No fall N fertilizer (except for fall-seeded crops), 50ft-no fertilizer(except corn starter)
Irrigation well within 8ft (100ft): For the 590 standard, no manure and fertilizer (unless through fertigation) may be applied within 8 feet of an irrigation well. For CAFOS, no manure is allowed within 100 ft of the well. If this is checked, the conduits to groundwater within 300 ft of field will get checked automatically as well.
Tile lines present in field: When unincorporated liquid manure and/or organic by-products are applied where subsurface drainage is present, 590 guidelines limit the rate per application to 12,000 gallon/acre. Note that this is a different determination from the Drained check on the Fields tab, which is used for adjusting N recommendations for corn.
Conduits to groundwater within 300 feet: This is checked if any of the direct conduits to groundwater are within 300 feet of the field. Manure applications on frozen or snow covered ground within 300 feet of direct conduits to groundwater are prohibited.
Possible Conduits Include:
oFractured bedrock at surface
oNon-metallic mine (a gravel or sand mine for example)
oOther direct conduit to groundwater
Notes: This box is for notes regarding the field and its restriction features that might be useful for application planning. These notes will show in the Restriction Explain column of the Annual Cropping Data Dump report.
There are several field restrictions which will "stick" if you turn them on when selecting certain ranges from the Below Field Slope Distance and Distance to Perennial Water options. To get these to be "unstuck," you first have to change the field setting to a value that is not in the "auto" restrictions range (Distance to perennial water < 300 ft, slope < 6%). This approach lets the planner set the SWQMA or Winter Slope restrictions and not lose these settings if they change field characteristics. When the field characteristics are in the auto range, then the Field Restrictions will show these as selected with a grayed-out effect that doesn't let you change it.
Note: On permitted farms the Field in 590 SWQMA restriction may be grayed-out and can only be changed if the WPDES-permitted farm checkbox is unchecked on the Farm Screen and then rechecked after the restriction is changed.