Calculating Cover Crop Benefit

[Shaggy98]

I've recently baled nearly 300 6' round bales of forage removed from a cover crop blend that I planted for weed suppression.  A local stock yard approached me and wanted to buy 200 bales delivered for $50/ton.  Due to the fact that I hired the haying of this crop I've got more invested in it than that.  However, since haying we've received nearly 5" of rain and the covers have taken off again and so far have extended excellent weed suppression.  If I'm losing money on the hay sale, how do I calculate the soil improvements the crop is providing?  I can easily calculate chemical savings, but I'm not sure how to determine an added soil benefit cost for soil improvements as well as erosion control.

[WCMO]

Those other soil benefits are probably hard to pin down, though there's probably some guestimator put together by some college or NRCS somewhere.  Don't forget to estimate/calculate the cost of nutrient replacement for that removed by haying the cover crop.

Try looking here, go down to where it says "cover crop economics tool" -- I didn't look at it yet, but it might be what you're looking for --

http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/il/soils/health/?cid=stelprdb1269028

[Jim Meade / Iowa City]

About $6/acre, Iowa State says.

https://www.extension.iastate.edu/ilf/sites/www.extension.iastate.edu/files/ilf/Cover_Crops_economic...

[sw363535]

Shaggy what would have been the soil loss if you had notilled it in a normal rotation?

My thought,,,, and I see this in several reports on the subject, Soil loss to erosion is very overrated.... and is needed to make the cover crop economics work....

Second thought ----- what is the loss of nutrient incured by bailing the crop and removing it.

Most of the cover crop examples are burned down in place to hold the nutrient level.

If you take a crop off, either by bailing or grazing there is a net loss of nutrient.  If you burn it down or work it in there lies the nutrition benefit.

My question is where is the soil benefit if nutrient continues to be taken?

[Shaggy98]

My reply to your question in a quick answer SW is "I don't know.  But what I do know is that we've had nearly 10" of rain and I haven't needed to use herbicide one time and the fields are still about 95% weed free.  I'm hoping the added OM will offset the nutrient loss, but the chemical savings alone as well as application costs IMO are worth something just not sure what yet.

[sw363535]

Good comments

Were the weeds not present or just get bailed with the feed?

and I guess it doesnt matter if the weeds didn't go to seed, especially with that much rain.

Had a neighbor who raised huge dry land crops in the 60's and early 70's but he was a dare devil when it came to the new fertilizer options of the time. and it was wet like that in those years....... He raised a healthy crop of weeds every spring, sometimes two feet high.  Then one way plowed them in --- or used a tandem disc. Planted-- applied herbicide and side dressed NH3 like it was going to rain and it did.

He never thought the weeds hurt a thing....... green manure..put back more than they use....

I always wonder if he should be considered a sloppy farmer, lucky, or a pioneer in cover crops...:)

[Shaggy98]

These fields were cleaned up with a burndown about 10 days before drilling.  In a few spots where the brassicas weren't as thick we had a kochia weed here and there but the covers must have stunted their growth somehow because they never were really a troublesome.  If it weren't for some volunteer milo that emerged after all the rain we would have virtually been weed free, but the youthful milo makes excellent feed as well.  My best yielding field so far has been 2850#/acre of cover forage on the first cutting & 3540#/acre of forage on a second cutting of regrowth. Evidently the volunteer milo weighs more than oats.  Planning on planting this field back to alfalfa in a few weeks so I'll get all the hay removed this week and start chemically preparing this field for no-till alfalfa planting.