Questions and Answers with Heather Darby

While towns and farms hit hard by Tropical Storm Irene are starting to get back to normal, a lot of work remains and repercussions are still being assessed. This is especially true for valley farms that were in Irene’s path. Many farms were flooded and, as a result, crops were damaged and fields were covered in silt, trash, and other potential contaminants. Farmers are making decisions about how best to move forward with this year’s crop and with the health of their soils.

We asked Heather Darby what she has learned in working with farmers since Irene. Heather is a sixth-generation Vermont farmer. She and her husband, Ron Hermann, operate Darby Farm, an organic vegetable farm in Alburg. Heather also travels the state as a UVM Extension Agronomist. She received her M.S. from the University of Wisconsin in Agronomy and her Ph.D. in Crops and Soils at Oregon State University. Heather is also a member of VLT’s Board of Trustees.

What kind of damage did farm fields sustain as a result of Irene?

The first loss experienced by many farmers was the destruction of crops. Some cornfields were steamrolled to  the ground and other fields were covered to the top of the tassels with heavy silt deposits. Vegetables were carried away or buried by sediment. Hay and pastures were covered with silt. In some cases, farmers lost entire fields as the soil was eroded away by the powerful water. Many farmers are dealing with finding adequate forage to feed livestock over the winter months. Others have no way to recover their losses.

What are the immediate and longer-term risks to agricultural soils from the flooding?

The problem of flooded fields does not go away once the crops have been dealt with. Now and into next year, farmers affected by flooding will need to work on reclaiming and rebuilding fields.

One of the biggest challenges was the quantity of silt, sand, and clay that was deposited on fields and crops. Many streams channeled into fields, severely eroded soil, and left lots of stone or silt. On average, we’ve been seeing fields covered with 6-10 inches, but many farms have fields where part, or all, of the field has 1-3 feet of sediment.

If there is a lot of sediment, farmers are trying to remove it, or spread it out and plow it under. Some farmers have scraped the sediment from fields, which was then used in rebuilding roads. Others have simply made piles just to get it off the fields. In other cases, folks have worked to incorporate it; however, once this is done, crop productivity could be reduced because of the low nutrient value in much of the sediment.

Also, sediment deposits were uneven in many fields: one-foot deep in one area and one-inch deep in another. In places where the sediment deposits were very deep, it’s hard to mix it in. Adding significant amounts of sediment will change the overall nutrient content of the soil. Obviously for some it will reduce the overall health of soil; in these cases it could take farmers years to rebuild the condition of their soils.

The longer-term impact is the largescale damage to fields where the soil was completely eroded away. There are farmers who lost four or more acres of land that will never be recovered.

Usually people think of flooding increasing the fertility of soil. Why are we hearing about loss of nutrients?

The nutrient value of the sediment depends on where the sediment came from. With Irene, the sediment came from the rivers, streams, and brooks, and also the mountains. A lot of it was sandy (as opposed to clay) and sandy sediment doesn’t hold nutrients. It does have some iron but little to no potassium or phosphorous.

In the mountain areas like Rochester, we didn’t see any value in the sediment at all; it was very sandy and stony. Because of the low organic matter in the sandy sediment, it will take time to convert the fields back to the original nutrient value.

What are farmers doing to assess the usability of their corn and hay crops this year? What are they finding?

Many farmers made decisions in September on whether or not to harvest flooded feed. They have been testing feed coming out of the flooded fields for mycotoxins (toxins produced by some fungi), ash (sediment), and heavy metals. Additional testing will be done once farmers start to use fermented flooded feed.

Through some screening of forage samples, the University of Vermont Extension has found little presence of mycotoxins in our initial testing. Nor did we find any harmful heavy metals such as cadmium. However, we did find that the feeds were moderate to extremely high in ash content; this has so far been the biggest issue because it can be harmful to animals.

While all forages have a base-level of ash content that is considered normal, we are finding that the ashcontent of the flooded feed is high.

There’s not a lot of data to say what happens when animals eat dirt, but they are certainly not getting any energy or protein from it. Because the animals are filling up on ash they aren’t filling up on the nutrients they need. This can lead to production problems in the cow.

Farmers are working with nutritionists to figure out how to dilute feed that has high ash content.

What have been the immediate challenges for vegetable farms in terms of silt and soil? What will be the long-term challenges?

Vegetable growers have many of the same soil issues. They unfortunately did not have the option to test vegetables; they were thrown out Soil Recovery After Irene altogether. The microbial population of soil is powerful, and one of its functions is to degrade contaminants. Soil has a natural ability to break down organic compounds and cleanse itself. Because vegetable farmers couldn’t plant fall crops, many are using cover crops to help bring soil structure, microbial activity, and fertility back to their soil.

What kind of help is out there for farmers?

UVM offers a couple of testing resources to farmers. Our Agricultural and Environmental Testing Lab tests for heavy metals in forages and soils. Farmers can contact Joel Tilley at (802) 656- 3030. Our Grain Quality Laboratory offers mycotoxin tests. Farmers interested in this can contact me at (802) 524-6501. There are also relief funds available; farmers should contact FSA and NRCS, and also the Vermont Community Foundation’s Farm Disaster Relief Fund.

How can non-commercial gardeners assess their soil?

Gardeners can have their soil tested for heavy metals. A good resource is the Master Gardener helpline at (800) 639-2230.

Are there any other things landowners should look for?

I think one big issue is the transfer of Japanese Knotweed into fields. It is a very noxious weed and the flood has spread the problem. We could see pieces of knotweed laying in a lot of the fields that we were cleaning up. If you can, pick it up and dispose of it. On a larger scale, not every piece will be easily found. Hopefully proper cultivation and forage management will minimize the spread of this weed. People should be out assessing their fields and looking for issues such as the spread of this weed.

What are you optimistic about given this difficult situation?

Farmers are taking the proper steps to do the testing. It’s their bread and butter. Many farms have had flooded crops in the past but with this storm it’s just more widely spread. There’s not a lot of extra feed available. There has been an outpouring of generosity among farmers—that’s Vermont. In all, this disaster has shown how strong Vermonters are. It’s shown how much every Vermonter cares for another by generous donations, lots of clean-up crews, and so forth. And, it’s shown how we can come together as a state in a time of need.