ASK Jeff: The Rodale Institute’s farm manager, Jeff Moyer, answers your hardcore farming questions

Have you calculated the down-pressure on each blade of your cover crop roller necessary to crush the stems of rye?

Posted July 2, 2004

What Jeff brings to the table

Jeff Moyer, who’s been the farm manager here at the 333-acre Rodale Institute research farm for more than a quarter of a century, receives lots of mail from farmers just like you asking for advice. Jeff’s hands-in-the-dirt experience over the past 26 years has run the gamut from refining the farm's cover cropping and crop rotation systems (including managing 270 acres in a rotation of corn, small grains, hay, and edible soy beans for a Japanese market) to overseeing The Rodale Institue Farming Systems Trial®, the world’s longest running side-by-side comparison of organic and conventional agriculture. We thought it would be fun and informative to share some of these farmer-to-farmer exchanges, and Jeff’s practical wisdom, with our readers … and we’ll be doing it on a regular basis.

Got a question of your own? Send it to Jeff at:

Dear Jeff,

I have been reading and researching the rye roller information on and anywhere else I can find information on the Internet. Have you calculated the necessary down-pressure on each blade necessary to crush the stems of a rye cover crop? I know this is going to vary with conditions, but any general rules of thumb?

Here's my scenario, and what I'm going to try:

Last fall I seeded 120 pound per acre of rye into bean stubble. I probably got a 90-percent stand that is about 5-feet tall today. It’s in head with pollen starting to shake off. We have a 15-foot Great Plains no-till (3-point, coulter cart). On the back of the drill is an Unverferth rolling harrow that is spring loaded for down-pressure. The harrow has helical bars that impact the soil much like the one that you built. Our exception is that the blades are serrated, forming a shallow vee that is on a 6-inch rise and fall about 3/4 inch depth. The rolling harrow diameter is approximately 12 inches, with a blade every 4 or so inches.
As I understand the methodology, we are trying to "crimp" the stem of the rye to prevent water movement. I will certainly let you know if it works or not. Do you have any initial thoughts on this?
Thanks for any reply or input.

Joe Woods

Dear Joe,

I don't really know the pounds per square inch of pressure we are exerting, but our roller (filled with water) must weigh close to a ton. When it rides on the ground, it basically sits on two blades that run its 10-foot 6-inch length and are 3/8 of an inch thick. For most of the material we roll, it isn't too much weight. The hitch has no down pressure, only the weight of the roller floating on the ground.

I hope that information helps. I see no reason that what you propose wouldn't work. I certainly would try it. Please let me know if it works. I'm always interested in new ideas.

Take care,

Dear Jeff,

Thanks for the input. I'll try to get some more information on the down pressure our unit has. If your unit weighs a ton, I calculate the following:

If your bars were in a straight line, I could assume:

Two blades in contact would equal around 21 psi—not really that much.

The picture shows the blades as helical, thus the contact area is probably a little less at any given time, so the pressure may be higher. At any rate, thanks for the input. I will report back when I get a chance. I'm located in Northwest Ohio.

Have a good day.

Dear Jeff,

Just a quick note on my drill experiment into rye: The drill listed below did a decent job in crimping the rye in one pass in the field; probably around a 70-percent knockdown. It broke the rye down at the root crown, and some of the bunches were also crimped further up the stalk. It is made up of 4 gangs, so there are 3 "blank" spaces where they come together, end-to-end. The rye that ran through that area was not touched.

Drilling the beans went east to west. Due to the lack of total kill, we then used the drill in the north-south direction as a roller, and used the coulter cart in the front to cut the rye into 8-inch long sections. Not the best of practices, but it probably simulates a buffalo rolling stalk chopper. I really like the results. With this said, it would be easy to construct a roller, place it onto an N-T drill, and have a "one pass" machine.

This drilling took place June 6. By June 11, I had beans coming out of the ground. We have been pounded with about 8 inches of rain since Friday, June 11. My dad and brother no-tilled some beans into bare ground, and if they didn't make it up they're basically rotten.

Last night I saw that I still have some sprouting and necking out of the dirt. In the past, my dirt turns into a parking lot when a heavy beating rain hits it. I am truly amazed by the "buffering" the rye does to the field. I do have some drown-out spots, but the rest of the beans look super. I had some late-plant corn, (planted June 8) that is dead after all the rain and heat. The seeds germinated in two days, then were drowned and cooked.

I am planning on building a 15-foot rye roller this winter to be able to use on larger acreages and following the drill, but the tool will be pulled by another tractor for versatility. This would be my first year in transition, (if I continue organic), and my dad's still on the fence. He's looking at other venues such as clover seed production. From reading, and talking to a few other organic farmers, I have the same story: washed out farm, herbicides not working, soil in bad shape. Oh well, time will tell.

Joe Woods

Hi Joe,

Thanks for the update. Your work sounds very interesting. Do you have any photos you could email me? I'm very interested in what you did, especially since it sounds like it’s working. Please keep me posted.


Dear Jeff,

I will snap some photos when I get a chance. I don't have a digital camera, so it may be a few weeks to develop, and scan. Have you thought of a roller that would work in place of a cultivator—say, plant corn into crimped-down red clover or other crop and when it grows back, roll it down in between the rows, create a mulch layer, and give the corn another boost? Just a thought; I've never seen farming done this way before, but I'm pretty excited about this alternative technology.

Joe Woods


Dear Reader: We’ll post a picture of Joe’s roller when it comes in and will keep you apprised of his progress as he experiments with alternatives to conventional agriculture and contemplates organic transition. NF


Have some questions to Ask Jeff? E-mail him directly at