Rock and Roll Agronomy

CRP: With Current Prices and Costs, What is the Best Thing To Do With It?

By Jason Hanson,Certificed Crop Advisor
jlhanson@landolakes.com

There is a considerable amount of interest in what to do with CRP acres. Is it worth taking it out of grass and putting in a wheat or corn crop when prices are this high? Or is the reason it’s in CRP because the gravel layer under most of the field made it limited in profitable crop production in the first place?

I think it would be wise to revisit the soil production maps from those fields and also look at how the internal drainage would affect profitable crop production. High salts, poor drainage and deep sloughs would not be my idea of land that could give the best return on investment. But maybe some of that soil would be good for things like glyphosate tolerant corn, which wasn’t at the same technological advantage it is now. We have more options to put on those acres, but what is the best way to get that ground ready if the decision is made to put that land back into production?

I am not a big fan of burning off fields in the fall with the plan to no-till into them with either Roundup Ready corn or soybeans just because weed control next spring will be a bigger challenge than if the same fields were hit with glyphosate in the fall. The burn off will provide a decent firm seedbed to direct seed into (outside of gopher and mole mounds) but weeds will be a bigger headache in the spring. Direct seeding would be the approach I would take to get the benefits of the CRP but I would probably favor a fall burndown of a higher rate of glyphosate and then let the weeds sit as long as possible to get maximum benefit on kill. Sometimes the grasses in CRP, quackgrass and brome species will be turning brown in Aug. or Sept. These weeds do need a higher rate of glyphosate, mostly the brome, so don’t cut rates thinking it will do the job. If grass is looking like it will lose some leaf material before  it’s time to spray, it might be best to clip or mow those fields to get the grass to green up, moisture permitting.

Having green leaf material is critical to good control
What to do when you want to till that ground? My experience is that first you have to get a handle on the grass because the amount will not flow through a chisel plow. I prefer to kill the weed mass with glyphosate and 2,4-D and then tackle it later after the biomass has died down and the roots have been destroyed. Even then, it’s tough not to get piles, mounds and a mess. Tillage destroys soil structure and CRP acres should have better organic matter content than tilled fields. Use that to your advantage. I am not a real big fan of working these fields in excess.

The other thing to consider will be the crop to put into that field. Soil testing is a must, as you will find that these fields will be very, very low in nitrogen and phosphorus. I have talked to people that have taken samples and the nitrogen rates have been under 5 lbs. per acre on a consistent basis. I don’t think you can convert CRP to crop production without a soil test. Even soybeans are going to need some nitrogen, and for sure, an inoculant. So when you start talking corn or wheat, it is going to be some large dollars for fertilizer. Placement will also be tricky when you need a lot of product and no-till is the option of planting. At some point, top dressing will more than likely have to be done. I would also see if any of these fields have long residual herbicides applied to them for canada thistle control like Tordon or Plateau. That could limit your intent of going in with soybeans or sunflowers.

A couple of other things to think about are insects and disease. As critical as the soil test is, I don’t think you can plant into CRP ground without using a seed treatment to protect from both insects and disease. But insects would be very critical as you will contend with wireworm, grubs, and the egg laying areas for grasshoppers. Most corn and sunflowers are treated with an insecticide, but soybeans and wheat would need to be treated. I am concerned with wireworm in these fields. Disease on grass crops like corn and wheat would be an issue like root rots or potential for head scab to some degree. Whatever the case, some fields might even have pest pressure that treatments might not be able to handle.

Weeds will always be an issue, so that is why I favor a fall burndown program even if it’s going into Roundup Ready crops. Perennial weeds that emerge in the spring will need higher rates as the plant is growing and not moving nutrient down to the roots like in the fall. The cool and warm season grass crops will provide better options on broadleaves than just glyphosate alone. Rotation will also be a big factor in utilizing moisture and weed management.

Current soil moisture levels and the water holding capacity of that soil during the growing season are also a concern. Late season crops will need a good supply of moisture to maintain profitable yields. Again, know your soil types and regional situation.

Some tips to consider:
Cereals

• Treat seed with insecticide and fungicide
• Plant a little heavier to compensate for field situations
• Pay attention to weeds

Corn

• Stick with glyphosate tolerant hybrids
• Consider extra protection with treated seed for insects
• Early weed control and broadleaf helper good idea

Soybeans

• Treat for insects, disease and double inoculate
• Stick with glyphosate tolerant beans
• Be aware of weed emergence

Sunflowers

• Only do if burned down last fall with glyphosate
• Burndown in spring again with Prowl or Spartan
• Consider extra protection from soil insects

Canola

• Use glyphosate tolerant hybrids
• Be very aware of seed placement and depth

In all crops, review your soil productivity and weigh which one would fit the best agronomically. Absolutely do a soil test and plan that this ground might take a little more due to mineralization affects and amount of residue. Seed to soil contact is important for all crops listed. Access to good direct seeding equipment is necessary for converting CRP to CROP.

Hanson is a certified crop advisor, and rocks and rolls near Devils Lake, N.D. as regional agronomist with Agriliance/Croplan Genetics.