SnapPlus uses a subset of the tillage options available in the RUSLE2 database for each primary tillage category. The tillage options in SnapPlus are selected to be on the higher end for soil disturbance for the typical range of those implements in Wisconsin. By using the more soil disturbing representative tillages, SnapPlus simplifies the process of calculating soil erosion while providing as much or more soil protection as the soil loss calculated in a conservation plan.

The fall and spring tillage options are defined as follows (note that fall tillages are recorded for the year the crop they were preparing for is harvested. Example, fall tillage done in the 2008 calendar year is entered on the cropping screen for the 2009 planning year for crops harvested in 2009.).

•Fall chisel, disked: Fall chisel plowing (twisted shovel) with spring disking (tandem light finishing) and field cultivation before planting.

•Fall chisel, no disk: Fall chisel plowing (twisted shovel) and field cultivation before planting.

•Fall Cultivation: One field cultivation in fall, use for one-pass fall tillage systems with no tillage in the fall.

•Fall MB plow: Fall moldboard plowing with spring disking (tandem light finishing) and field cultivation before planting.

•Fall vertical tillage: Fall pass with a seedbed conditioner consisting of a double gang coulter caddy, rotary harrow and rolling basket incorporator, plus a spring pass with the same seedbed conditioner.

•Spring chisel, disked: Spring chisel plowing followed by disking (tandem light finishing) and field cultivation before planting

•Spring chisel, no disk: Spring chisel plowing and field cultivation before planting

•Spring Cultivation: One field cultivation in spring, use for one-pass spring tillage systems.

•Spring MB plow: Spring moldboard plowing followed by disking (tandem light finishing) and field cultivation before planting

•Spring vertical tillage: Spring pass with a seedbed conditioner consisting of a double gang coulter caddy, rotary harrow and rolling basket incorporator.

For more information on the SnapPlus tillage systems and how to choose one that is representative of the soil disturbance for your tillage system using Soil Tillage Intensity Ratings (STIR), see Matching SnapPlus Tillages.

Not all of the tillage options are used for all crops in SnapPlus because some crops are not typically grown with the full range of tillage systems.

Double crops: When there are two crops in one year, either one or two tillage systems are displayed for each listed selection. If only one tillage system is named, these tillage operations are assumed to be completed before the first crop and then repeated before the second. All of the operations will be done for both crops.

If a different tillage system is given for crop 1 than for crop 2, the crop 2 tillage describes the operations between the first and second crop. The definitions for the crop 1 and crop 2 tillage systems are the same as those listed above for single crops. A Disk for crop 2 is a tandem light finishing disk.

Cover crops: For crops that include a cover crop, tillages are listed for the primary crop. The cover crop is either no-till or disked (tandem light finishing disk). Example: "Fall Chisel, no disk, cover crop disked".

Injected manure and anhydrous ammonia: If manure with the spread method Injected or anhydrous ammonia with the spread method Subsurface is applied in a no-till or strip-till system or in a season when there is no tillage, SnapPlus will automatically include the effects of the injection operation in soil loss calculations. The manure injection will use the RUSLE2 operation "Manure injector, liquid high disturb. 30 inch" and the anhydrous injection will use "Fert. applic. anhyd knife 30 in"

Diversified vegetables: This crop choice is intended to represent double-cropped organic vegetable production systems. The "Tilled" option assumes two leafy green vegetable crops per season with a spring moldboard plowing, two tandem disk passes, and a roller operation before each crop. "Tilled, organic mulch" is the same as "Tilled" prior to the planting of the first crop, when 3 ton acre wheat straw is added as mulch, and there is no tillage for the second crop, which is hand planted. "Tilled, plastic mulch" has the same tillage operations as "Tilled" with the addition of plastic mulch covering 75% of the surface applied at planting and removed after harvest for both crops.

Diversified vegetables (single crop): This crop choice is intended to represent organic vegetable production systems with one crop per year. Primary tillage choices are Fall chisel, disked; Spring Chisel, disked; Spring chisel, no disk; Spring chisel, disked with organic mulch; and Spring chisel, disked with plastic mulch. For all of the single crop diversified vegetables except for those with mulches, the tillage systems follow the SnapPlus definitions given above plus a row cultivation for weed control. The mulching operations for  "Spring chisel, disked with organic mulch" and "Spring chisel, disked with plastic mulch" are the same as those described above for Diversified vegetables.

 

Note: SnapPlus won't compute soil erosion for crops that do not have RUSLE2 management templates appropriate for Wisconsin.  These are crop that display the word Any in the tillage box. These crops include Brassica forage, Broccoli, Brussels sprouts, Cauliflower, Celery, Hop, and Lettuce. The Diversified vegetable cop choices may be suitable substitutes for some of these crops,