Cultivating Questions Farm Tour Follow-Up

Cultivating Questions

Concerning the Bio-Extensive Market Garden

by Anne & Eric Nordell of Trout Run, PA

Farm Tour Follow-Up

In this column we finish cultivating a selection of questions from the 2012 farm tours. We also respond to a question from a group of forty extension agents who toured the bio-extensive market garden in 2010. We thought their concern about managing horse manure in the vegetable fields was timely to address given the recent release of the FDA’s proposed Produce Safety Rule.

Fortunately, the proposed rule allows for the use of work animals on produce farms as long as the growers can demonstrate that precautions have been taken to prevent contamination of the vegetables. The ball is now in our court to prove that horse-powered market gardeners are conscientious about food safety. Food safety experts we have talked to suggest the best way to do this is to have on hand a written risk management plan detailing the steps taken to prevent raw manure from coming into contact with the crops.

We conclude this CQ with the first draft of a produce safety plan for our farm. We have also included a few tips on risk management regarding work animals from a couple of organizations that have a lot of experience dealing with this topic in the wholesale marketplace.

Q: I noticed the wheel attached to the sicklebar mower in your machine shed. Is that what you use for double-cutting the cover crops?

We put the wheel on the end of the cutterbar for topping the horse pasture. To support the bar 10-14” off the ground we replaced the outer shoe with a walking plow depth gauge wheel and hoisted up the push bar with a chain wrapped around the tongue. We got the idea for this improvised setup from studying the illustrations of weed clipping attachments in Lynn Miller’s Horsedrawn Mower Book.

Cultivating Questions Farm Tour Follow-Up
For clipping pastures and riding high over regular obstructions manufacturers used to provide an option of an adjustable bar wheel which clamped on the end of the bar.

We do not use this pasture topping setup for the cover crops because the team and the mower wheels would tramp down too much of the tall stubble. Instead, we use two different strategies for cutting the cover crops into manageable-sized pieces for incorporation. If we want to extend the cover crop growth period as long as possible and keep the residues relatively succulent, we use the cut-and-come-again system shown in the Weed the Soil booklet and video where we repeatedly mow the rye whenever it reaches knee-high. If we want to maximize biomass production and increase the C:N ratio, we allow the cover crop to grow until pollen drop and double-cut it, making the first pass around the field with the cutterbar in the transport position (angled 8-18” high), and then going back over the same swath with the cutterbar dropped to the ground. We can make this switch on-the-go simply by using the lifting arm level to pop the pawl from the upper to lower notch.

Cultivating Questions Farm Tour Follow-Up
The lifting pawl mechanism in each of its positions.

Q: Doesn’t the mower plug up?

We have not found that to be a problem with either method of recutting stalky cover crops like rye, oats and sorghum-sudangrass. However, a tall wind or cross wind can cause the top-growth to fall forward or sideways on the cutterbar, preventing the mower from cutting properly and dumping clumps of cover crop residues in the field which can interfere with the next clipping and tillage.

Q: Your leeks look nice. How did you plant them?

We plant the leeks the same way we plant the onions, opening a narrow furrow with a 1” tooth on the riding cultivator and then setting the plants by hand, 2-3” deep and 7-8” apart in the row. In the case of the four rows of leeks planted along the north side of Field 3 in 2012, we set them out the last week of May, zone-cultivated the crop on 6/8 and 6/14 to maintain a soil mulch around the small plants, and then mulched the pathways with rye from the adjacent fallow Field 2. Minimizing cultivation and the depth of planting keeps dirt out of the leeks, a quality our customers really appreciate.

Cultivating Questions Farm Tour Follow-Up
Mulching leeks in Field 3 with the rye cover crop in Field 2. To save a few steps we made a few extra rounds with the side delivery hay rake to move the windrows of rye on the south half of Field 2 closer to the edge of Field 3. (Rye on the north half of Field 2 was used to mulch zucchini and peppers planted along the south edge of Field 1.)

Q: How did you mulch the leeks?

We mowed the rye in Field 2 when it was 5-6’ tall on May 21, then raked it into windrows on 6/11. After the second cultivation of the leeks on 6/14, we moved the windrows into the pathways by hand.

We should point out that when using the cover crops for mulching the vegetables we do not use the double-cut or cut-and-come-again mowing systems. We prefer to cut the cover crop close to the ground when it has reached its full height because the windrows of long stem rye are easier to place in the pathways by hand, do not blow away in a stiff wind, and take much longer to decompose than cover crop residues chopped into small pieces. In fact, we often get two to three uses out of the long stem mulch. For example, at the end of the growing season we moved the rye mulch in the leeks to the strawberries in the middle of Field 3 for winter protection.

Q: It seems like you are removing a lot of organic matter from the fallow fields. Have you noticed any changes in the soil or crop production since using the cover crops for mulching?

That’s a little hard to say because there are so many variables affecting crop growth and soil quality. At this point, we would say that soil tilth when planting the vegetables is better when we work the preceding fallow year cover crops into the surface of the soil. On the other hand, when we remove the fallow year cover crops for mulching, slug pressure in the following vegetables is lower. Removing the cover crop top-growth also makes it much easier to use minimum tillage to incorporate the cover crop stubble.

In the long run, we are not worried about robbing cover crop organic matter from the fallow fields. Afterall, we are not removing the cover crop organic matter from the farm, but simply moving it to different parts of the market garden. Also, 40-50% of the cover crop carbon remains in the fallow field with the root system and stubble. We always follow the rye cover crop used for mulching with the second substantial cover crop planted in July (sorghum-sudangrass and/or clover) or early August (oats on ridges). Coincidentally, we started a pasture pooper scooping project about the same time we got serious about growing our own mulch. We use the extra compost from the pasture manure in the fallow fields to increase cover crop biomass production and replace the organic matter and nutrients removed with the cover crop mulch.

Q: What about using the cover crops for bedding the horses?

We tried that once. Bringing in the rye with the horses and hayloader was fun. However, the waxy, long stem rye was not very absorbent – and not much fun to fork out of the horse stalls. We should probably try it again using the double-cut system to mow the rye into smaller, more absorbent pieces for bedding.

Q: What precautions do you take to prevent food contamination from the horse manure?

To a certain extent, the bio-extensive system reduces the risk of food contamination. For example, due to low weed pressure from taking land out of production, we usually discontinue cultivating the vegetables 2-4 weeks after planting. Consequently, there is very little fresh manure dropped in the fields close to harvest of the cash crops.

The bio-extensive method of applying horse manure compost to the cover crops well in advance of planting the vegetables also fits in nicely with the current 120 day rule for “raw manure.” (Our hog composted horse manure is classified as “raw manure” because it does not meet the federal composting requirements.) Under the proposed FDA regulation, the time period between applying “raw manure” and harvesting high risk produce will be increased from 120 days to 9 months! If this becomes law, at least we have the option of applying all the horse manure compost to the fallow fields the year before production.

We must admit that we were not concerned about the small quantity of fresh horse droppings in our vegetable fields before receiving this question from extension agents who work with Amish produce growers in Southeastern Pennsylvania. To get up-to-speed with the rest of the horse-powered industry, we subscribed to Truck Patch News ($18/year, PO Box 101, Mount Hope, OH 44660) and ordered a copy of The Farm Food Safety Plan ($7/copy from Yoder’s Produce, LTD, 9599 S. Apple Creek Road, Fredericksburg, OH 44627) which was put together by the Food Safety Education Team for the rapidly growing number of produce auctions in Indiana, Kentucky, Ohio, Pennsylvania and Missouri. We also contacted Equicert (209 West 1st St., Clarence, IL 60960, 847-970-0131) which offers food safety audits and a certified horsepowered program for wholesale produce growers.

These resources recommended removing horse droppings from the produce fields between planting and harvest or burying the fresh manure in the soil, whichever is more sanitary for the crop and the grower. For high risk vegetables, it may be advisable to flag the area and avoid harvesting within several feet of the drop site. These sources also emphasized the importance of personal hygiene, especially for those who handle the horses. Consequently, many Plain produce operations now use harvest wagons equipped with hand washing stations.

With this advice in mind, we put together the following risk management plan for the 2013 growing season. Even though our small, direct market business would be exempt under the proposed FDA rule, we tried to cover all the areas of concern in this government regulation.

Domestic and Wild Animals

We do not graze livestock in or near the produce fields. We rely on work horses for all aspects of field work including seedbed preparation and cultivation. All manure dropped by the horses in the produce fields after planting is removed from the field or buried where it is deposited. In the case of high risk crops such as spinach and salad mix we destroy the crop in the immediate vicinity of the droppings. We do not use the team for spraying, harvest or transporting the vegetables to the packing shed. Two exceptions are garlic and potatoes which we use the horses for lifting and/or transporting the crop to storage. Both garlic and potatoes are considered low risk vegetables because they have a protective skin or are cooked before consumption.

A sloped, high-tensile electric fence keeps deer out of the vegetable fields. We maintain knee-high barriers across all openings to our hoophouses to keep out rabbits, wood chucks and neighborhood dogs and cats. Tacking bird netting under the rafters of our packing shed has successfully deterred English sparrows and other birds from roosting in this facility. Although the packing shed is located near the horse stables, we do not see flies in the well-ventilated structure.

Biological Soil Amendments

As certified organic growers, we follow the National Organic Program standards for using animal manure. Since our composted horse manure does not meet the NOP standards for “compost,” we use the guidelines for applying “raw manure,” spreading the compost at least 120 days before the harvest of small fruits and vegetables. When applying this non-NOP compost next to fields with established produce, we disengage the widespread on the manure spreader to prevent spreading compost into the adjacent vegetables.

We finish a small portion of the horse manure compost in a tumbler which meets the NOP standards for in-vessel composting. We use this NOP compost for hoophouse production, potting mix or other applications where it is not practical to follow the 120 day rule. Tools and equipment are dedicated to handling NOP and non-NOP compost to prevent cross-contamination.


We do not irrigate the crops grown in the fields. In accordance with organic certification requirements, the spring water we use for washing produce and irrigating the hoophouses is treated with an ultra-violet light. Annual water testing confirms that the water is potable and does not contain any form of e. coli. Due to concerns about hydro-fracking the Marcellus Shale, we also test the water annually for drilling contaminants.

We use a food-grade hose to deliver wash water in the packing shed. Salad mix is triple-washed, spinach double-washed, and heads of lettuce dunked and hosed off on a screen. We use small dunk tubs for these greens and change the dunk water frequently.

Personal Hygiene

We use the rest room in our house for hand washing before picking and packing. We are in the process of setting up a simple hand washing station at the entrance to our packing shed to make hand washing more convenient when coming in from the fields. We have boots, sweatshirts, hats, gloves, aprons, etc… dedicated for work in the packing shed and harvesting salad mix, spinach, lettuce and other high-risk produce.

Our part-time employee is also a cook and already trained in food safely protocol. Employees at our stand at the farmers market are also very conscientious about personal hygiene.


We maintain an audit trail for organic certification composed of invoices, harvest records, applied amendment records, planting calendar and field journal.

What Are Our Risks?

In the case of horses used as a power source, this is a safe practice provided we keep it that way. Keep in mind, if it came out of a horse, make sure it doesn’t contaminate any food source…

Horses should not be in the growing crop rows within seven days of harvest. Throughout the harvest season the horses should be limited to the harvest driveways…

When laying plastic mulch, make sure the driveways for the horses are a minimum of 10 feet wide and seeded with grass. Use these driveways as much as possible…

Change boots from the barn to the packing house or field…

Have a hand wash station with soap, water and towels close to your packing table or area. Make it easy to wash hands…

Do not apply manure after February 1st or follow the 120 days before harvest rule. Use good judgment. Situations vary according to soil types, slope, climate, and what crop you are raising. Be careful when you spread so water runoff or wind will not carry it into your crop or water source. Check with your local or state manure handling laws.

• selections from the Farm Food Safety Plan – Guidelines and Procedures

On January 4th, 2011, President Obama signed the Food Safety Modernization Act paperwork and gave it to the FDA to write rules and standards on growing, harvesting, and packing vegetables and fruits. The task at hand was, in a nutshell, to make fresh produce in the United States less likely to contain any pathogens that could make anyone sick….

The FDA visited different areas, different states and a lot of different size farms to try to understand what kind of standards could be used across the United States and work so they don’t create hardship. It so happened that one of the visits was made in the Holmes-Wayne County, Ohio area. Farmers Produce Auction, Mount Hope, Ohio was visited while in session. The quality of the produce and the happy families were the two key points that were made in a letter to me as a Thank You. The visit was done to inform them of what is being done in some areas to bring an income to the family farm. FDA visited farms in California as well as many other areas. Some public meetings were held, but the farm and auction visits gave them more insight on what is really going on in the produce farming world… The FDA decision makers had no idea anyone farmed with horses anymore.

• Raymond J. Yoder
Chairman, Food Safety Education Team
April, 2013 Truck Patch News

Do I have to diaper my horse?

Probably not. I don’t know very many people who are doing it. The standard and the auditor look to you to tell us how you avoid risk on your farm. That’s commodity specific. Is a horse in the field a risk to sweet corn? Not hardly. How about pulling a wagon through strawberries? Now, maybe you have a case for a horse diaper. I don’t like them myself because too many horses react to them like you tied a feed sack to their tail and gave them a swat on the behind. Some will tolerate them, some won’t. Some very serious situations have developed at parades where they were required when the horse suddenly felt that thing bump him and reacted accordingly. Another risk factor is that you will handle manure from a parade bag with your hands. What will you touch next?

You have a lot of options. You can mark contaminated produce with a flag and not harvest it. You can destroy contaminated produce immediately. You can change your methods, like stopping cultivation a certain time before harvest. Carry a shovel under the harvest wagon and bury manure immediately? All these things can reduce risk, but we are counting on the farmer to tell us what works for him. And if you have a tired old nag that doesn’t mind a horse diaper, I won’t tell you not to put it on. Just put down the methods you use to reduce risk in your farm safety plan.

• Michael Hari, Equicert News
Fall/Winter 2012-2013 issue

What is Equicert?

Equicert is a farm service business that exists to help keep old order farmers farming through programs like our food safety GAP and GAP GFSI audits, our GHP audits for auctions and coops, our certified horse powered program (that helps sell horsepowered farm produce at a higher price through a certifications process like organic certification), the fossil fuel free certification program (that helps shops that do not use fossil fuel to sell to environmentally minded customers), and through our other programs like Equicert News.

There is nothing wrong with shop work, but our communities change when there is no one left farming. Our purpose as a business is to help keep our people farming – and it is at the heart of everything we do.

What is an Equicert certified horse-powered farm?

An Equicert certified horse-powered farm uses horses (or other animals like oxen) or manpower to grow agricultural products. The use of tractors is not allowed. We also do not certify genetically modified crops (GMO) or farms that participate in government payment or subsidy programs.

209 W. 1st St North
Clarence, IL 60960