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

Does organic farming increase an area's weed population?

Posted April 12, 2007

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? Click here to send it to Jeff.

Dear Jeff,

At a recent public farm forum, a local conventional farmer mentioned his concern about livestock enterprises going organic in the area because the organic hay they purchased was full of weeds. He felt they would import foreign weeds as well as increase the weed population since most manure is not composted before applied to the land. Is this a real concern? How would you respond to this issue?

Alan Shank


Dear Alan,

Thanks for the question and for reading New Farm. I’ll start by saying that organic is not, and should not be, an excuse for poor farm practices. Yes, there may be specific instances where weeds may get out of hand, but organic farmers who are doing things right should be able to manage weeds in a responsible manner. Hay crops are no exception. Our organic alfalfa/grass hay fields are generally no weedier than our conventional neighbor’s. They are planted as part of a sound crop rotation, using high-quality seed, planted into healthy soil and harvested at the proper time. When it is time to rotate them out of hay, we do that. Hay, crop rotations, use of cover crops, applications of compost and cultivation practices are all part of a weed management strategy that can work well to prevent weeds from ever getting out of control.

It is true that many farmers, including organic farmers, don’t compost their manure. Personally I think they should. Composting can kill weed seeds that might otherwise pass through the animal’s digestive system still intact. But keep in mind this is also true for conventional farmers. Few of them compost, and weed seeds move onto their farms and can be spread with manure as well.



Dear Jeff,

Thanks for your reply. I'm a dairy planner with the Snohomish Conservation District in Everett, Washington. I haven't had experience with organic hay production or completely organic pastures. We have a few dairies that are starting or looking into going organic. Your response seems pretty solid to me. Can you point me to any resource that instructs on how to manage and produce organic hay?

Alan Shank



If your farmers have experience in growing and making hay conventionally, they should have no problems doing it organically. The big difference is in how you get the hay established. Since you cannot use herbicides to help the slow-to-establish alfalfa or perennial grasses get going, you need to consider timing and the use of a nurse crop. Frost seeding into a nurse crop of winter grain works here in the East, as does establishment into a spring-planted nurse crop of oats or other spring grain. Once the hay is up and growing, it can out-compete the annual weeds. Making the hay is not really any different from conventional to organic. Cut it at the right time and get it into storage in the best condition possible. Good luck, and let us know how the transition is going.