Since you must be cutting the Rye before it sets seed there may be some you seeded last fall that are germinating after you plant. I just "weed whack" mine and have not seen any new growth after doing that. The stalks stay on the soil surface as mulch which does make planting a bit tricky sometimes.

I have grown it for years and it seems to me that mowing is more effective on mature plants. My crop this year was planted with Austrian peas and I began cutting it off in early March. I did not mow it but I used a sharp round-point shovel to try to skim it at the soil line and then removed the top growth to add to a layered hot compost pile. I mixed alternating layers of last fall's leaves, the cover crop tops, wood chips and finally a liberal sprinkling of rabbit food. The kill was relatively good although I still have to eradicate the occasional plant that is re-sprouting from the base. I wanted to leave the massive amount of roots in the soil to feed the organisms there and I didn't want to till the soil and harm the structure or the biological order that has developed. For setting transplants I inserted a garden fork downward fully and then pulled back on the handle to loosen and slightly uplift the soil. As I do this I can hear the fibrous roots of the rye tearing. I insert the transplant and then firm the soil. My logic is that the roots would stay in place and feed the soil, I could utilize the top growth to get a quickly finished compost and I would not disturb the soil structure to any great degree. The compost pile yesterday reached 156 degrees and I will turn it to prevent material in the middle from becoming ash. My cover crop was so dense that I feared that the top growth remaining on the surface following mowing would slow my ability to plant. I am mulching then between rows and plants with fresh wood chips from a local arborist.

Old dirt: you might try feed oats instead. I plant mine with my gardenway planter, 9" rows on center, in mid August here in north-central KS. It took a couple of years of trial and error to get the planting time just right to get maximum cover and killing freezes before they go to seed; 2 weeks too late or early seems to make quite a difference. The one year they were planted too early I had to weed whack the plants to avoid them going to seed. The advantages are 1) good N mop up crop 2) good ground cover for winter and following summer if left un-tilled and 3) greatly improves soil tilth 4) for me, the seed is free and very easy to plant, one overhead watering after planting and I'm done. 5) complete winter kill.

Oats would be a good early spring cover crop but since the cold winter, around here, kills the plants off they do not make a good winter cover crop, someting growing to help hold the soil from being blown away by the winds. When I have planted Oats I have just thrown the seeds around by hand, just as I do the Rye, and lightly raked them into the soil. I'd think a single row planter would take much too long to use.

kimmsr: does the cold kill your oats before they get much growth if fall planted? If so, try planting earlier I guess. Mine get about 2 1/2 - 3 ft tall and are dense enough that they completely cover the ground especially after the hard freezes do them in and they lay down. I intend for the killing freezes to kill the oats. BTW, my oat cover is supposed to die because I plant into it the following year. With the plant material laying on the ground throughout the winter and into summer, if I let it, there is no way even a KS spring thunderstorm will penetrate that dense mass with soil pounding rain. The dense mat is also very good at supressing weed growth the following year.

The planter usually takes me about 20 min to plant about 1800 sq ft., wouldn't want to do an acre that way! Originally, I was going to scatter the seed and rake it in but decided to try the planter, it worked so well I haven't yet experimented with the broadcast method.