SnapPlus Help Version 19

About Cover Crops in SnapPlus

About Cover Crops in SnapPlus

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About Cover Crops in SnapPlus

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All "cover crops" in SnapPlus are assumed to be unharvested, with all residue staying in the field. For harvested forage crops that provide over-winter cover, select an appropriate SnapPlus forage crop rather than a cover crop. Cover crops always follow a harvested crop (example: Corn silage to small grain cover crop) and overwintering forages always start in the fall of the crop year they will be harvested (example: Winter rye (forage) to Soybeans g+s, 15-20 inch row). Since cover crops are not harvested, they do not have recommendations for added nutrients and the SnapPlus nutrient balance calculations assume they do not remove P2O5 or K2O from the field.

 

Cover Crop Type Definitions

 

Small grain cover crop: an over-wintering cover crop such as winter rye that is planted within about a week after the main crop harvest and is killed with tillage or herbicides the next spring prior to planting.

 

Annual cover crop: a cover crop such as oats that does not over-winter. An annual cover crop is typically planted within about a week after the main crop harvest and is killed by winter freezing.

 

Interseeded or aerial seeded cover crops are planted into the growing main crop without soil disturbance. Growth of the cover crop is "released" by harvest of the main crop. These types of cover crops over-winter and are killed by tillage or herbicides the next spring prior to planting. There is no way to make a non-broadcast interseeded cover crop in RUSLE2, so for drilled inter-seeded cover crops, use the aerial seeded version.

 

 

Additional Notes on Planning Cover Crops in SnapPlus

 

For cover crops that are broadcast following harvest, use the no-till seeding choice.

For winter killed cover crops and cover-crop mixes, use the annual cover crop choices.

There are two crop choices for full growing season cover crops for fields where no regular crop will be harvested in that year:

Annual cover crop, spring-planted, not harvested,

Small grain cover crop, not harvested

For spring-planted crops following over-wintering cover crops, any tillage prior to seeding the new crop kills the cover crop in RUSLE2. For no-till and strip-till crops without a tillage operation prior to planting, the cover crop is killed by a spray operation 5 days prior to seeding. Note that this will cause soil loss to be slightly underestimated if the cover crop is killed more than five days prior to planting. For the no-till green plantings, the spray operation for killing the cover crop is put immediately before seeding the new crop in RUSLE2.