How an herbicide in "organic" compost is destroying organic soils - A cautionary tale.

Guest post by Bruce Olive, hobby gardener, Olive Farms in Orange County, NC.

On February 9, 2009, Dow Chemical registered the website URL www.BanAminopyralid.com. They haven’t developed a website yet, just purchased the domain and squatted on it. Kind of strange for the company who actually makes a product called Aminopyralid. For those of you who are not farmers or gardeners, the word Aminopyralid most likely has no meaning. But for UK gardeners last year, and for many US gardeners this year, this hormonal herbicide used to kill weeds in hay and straw fields has become a nightmare.

Early signs of aminopyralid poisoning include leaf cupping, fernlike growth, and twisted vines. Photo by Bruce Olive.

Here’s the deal. In the tightly knit coven of commercial chemical and seed producers (often one and the same), agricultural extension services and growers/producers, “programs” is how the work of the farm gets done. A “program” consists of soil amendments, herbicides, pesticides and seed stock genetically modified to flourish in this chemical bath. You plant the right seed, you spray the right chemicals, and everything comes up roses. But unintended consequences have a strange way of showing up where you least expect them. Take the case of Aminopyralid for example. You get a great yield of hay and straw with the “program”, using Dow herbicide products such as Grazon and Forefront. You sell the beautiful, thistle-free, weed-free straw and hay to local horse and cattle farms, who are totally pleased with the thistle-free product. The horses and cows eat the hay, and bed on the straw. You compost their manure and the straw bedding, let it cook for a year or so, and then sell it to compost packagers and vegetable gardeners as “organic” compost, just the way you always have. But you don’t have any idea the compost contains a toxic herbicide with a 533 day half-life. Then the local extension service begins to get calls about twisted tomato vines with curly leaves, wilting eggplant, and droopy potato plants. Strawberry producers loose a season’s crop. Suburban gardeners report wilting zinnias.

And then you suddenly realize that the herbicide was in the manure, passed on through the animals, and has now contaminated the soil. And may continue to contaminate the soil for years to come. Recently pulled by Dow from the UK market due to its devastating impact on vegetable and flower gardeners, the true impact of Aminopyralid is only just now being felt in the US. While there were some reports of impact last year, it seems to be in the application of aged compost this year that is being felt on a growing basis. We appear to be running a year behind the UK in our cycle, but the spring of 2009 will be remembered by many local farmers and market gardeners as the “Spring of Aminopyralid”, and the cascade of unintended consequences that followed its use. Soil remediation is possible but can take several years. For certified organic farms this contamination will be treated as “an act of God,” so they will not lose their certification but will lose the infected land until it can be remediated.

So when Dow registered www.BanAminopyralid.com back in February of this year, they were undoubtedly expecting someone else to want to register it shortly after. Or perhaps they were simply being good corporate citizens, preempting the public outcry. Where this will go is anybody’s business. Being America, the likelihood of a class action lawsuit is probably greater than the likelihood of a ban on the chemical. In the meantime, beware of putting any manure-based compost on your garden, whether from a big box store in a plastic bag or from a local farmer in the back of a truck. Not to place any blame, but to understand that folks may not even know their compost is toxic. Test all compost and manure with small plantings BEFORE you apply to your garden. Unlike herbicides such as Roundup, the hormonal herbicide lets the plant grow for quite a while before destroying it. What looks like a curly leaf virus or aphid problems may not be what you think it is.

Our own garden is ruined for this year, with hundreds of greenhouse raised seedlings destroyed. We are currently remediating this land following directions from the Rodale Institute. Not to be defeated, we have in the meantime plowed up another patch and put it behind some electric fence.


The first step in remediation is don’t give up – plant a new garden with a deer fence!

By all means, continue to buy local, but buyer beware….the Dow slogan "bringing good things to life" is not necessarily referring to the life of the things in your deer protected patch of Piedmont heaven.