Local Veggies

Worried about pesticide residues on your food? Well pesticide residues aren’t the major cause of food borne illness. Contamination of food by pathogenic bacteria and other organiss is probably more common. Many of these incidents go unreported making it hard to estimate the extent of food related illness. Cases of foodborne illness turn up fairly often with cantaloupe being the most recent.

If you are concerned with food born illness, are still worried about pesticide residues on food, or just like fresh veggies. Buy local! Local foods have been a hot topic lately and are catching on, even in my home state. This is probably due in part to the latest books by Michael Pollan, The Omnivore’s Dilemma: A Natural History of Four Meals and In Defense of Food: An Eater’s Manifesto.

Toxic Tomatoes

Continued from Wednesday’s post…

Food items such as meat, milk, celery, potatoes, are pictured and discussed in “The Dirty Dozen: Top 12 Foods to Eat Organic.” I can’t speak for the fruit, meat, and dairy items listed, but the statements about the vegetables crops don’t strike me as being entirely accurate.

Bell peppers, celery, and tomatoes are listed as having thin skins which in theory allows for pesticide contamination. The description of pesticide use on tomatoes is especially interesting, and is described by the following quote: “The standard regimen of pesticides used on conventionally raised tomatoes numbers 30. Their easily punctured skins are no match for chemicals that will eventually permeate the whole tomato.” After reading this statement I pictured tomatoes as being a big sponge, soaking up any all pesticides applied.

Are all tomatoes (and other thin skinned vegetables) laden with pesticides then? Well first there are maximum pesticide reside amounts allowed on food, described on the 26th. And produce is tested for pesticide residues. The volume of fresh vegetables consumed means that only a small portion of the vegetables are actually tested. A single tomato purchased from a grocery store probably hasn’t been tested for pesticide residues, but other tomatoes like it have. If regulations have been followed then it is likely that pesticide residues will fall within an acceptable range.

The characteristics of a tomato plant and its fruit mean that only certain pesticides can be used. For example say a new pesticide was being developed for use in tomatoes. After testing this product on tomatoes plants it was discovered that the pesticide was able to pass through the skin of the tomato. As a result of these findings that chemical could not be legally used on tomato plants.

Pesticides in Your Food

An interesting series of pictures called “The Dirty Dozen: Top 12 Foods to Eat Organic” turned up on msn.com recently.

As the title suggests the foods pictured represent some of those most commonly contaminated by pesticides. They failed to explain what exactly they meant by “pesticide contamination.”

Typically pesticide contamination is measured in parts per million (ppm). What is a part per million? Here is how I like to think about it, image a room with 1 million marbles: 999,999 of those marbles are green and one of those marbles is red. The red marble represents 1 ppm. Say there are 5 red marbles in that group of 1 million, those marbles represent 5 ppm.

Okay back to pesticide contamination. The article didn’t mention if the pesticide contamination exceeded the amount allowed legally or if the concentration of those pesticides allowed was still considered harmful. On the other hand they could be making the assumption that the food items in question are not being tested properly resulting in pesticide contamination.

It is really hard to determine what exactly they mean by pesticide contamination. The statements along with the pictures support all three cases listed above.

Just because a product is organic does not mean that it will not have pesticide contamination. There are some pesticides that can be used in organic agriculture. These products are approved by the Organic Materials Review Institute (OMRI). To see listings of what can be legally used in organic production visit the OMRI products list.

To be continued…

Bean Harvest

Pull and windrow vs. direct cut, which is the better way to harvest dry beans? There is some controversy about which method works better. But first what is pulling, windrowing, and direct cutting?

Pulling is probably the most common method of dry bean harvest. To me the term pulling is kind of misleading. I picture dry bean plants being pulled out of the ground by hand, just like weeds. Harvest of dry beans is usually mechanical and makes use of two types of pullers: knife and rod. These devices cut the bean plants just below the soil surface. The process reminds me a little bit of digging potatoes.

After pulling the beans are then windrowed. Windrowing is kind of like raking hay, the bean plants are moved into small piles that run the length or width of the field. The windrows are then picked up with a combine which separates out the seeds from the rest of the plant, this process is called threshing.

Traditional dry bean harvest methods require several passes over the field and can be time consuming. For this reason some growers have moved to direct cutting their beans. Direct cutting requires one pass with a combine which cuts and threshes the beans at the same time.

Why would beans be pulled and windrowed instead of directly combined? After all self propelled combines have been around for quite awhile. The main problem with direct cutting is that it tends beat up the beans a lot more. Damage is more visible on lighter colored varieties like those in the light red kidney class. Darker beans like black turtle soups don’t show as much damage.

The salability of direct combined beans comes down to visible damage. Buyers may discourage direct combining, but if the beans look okay then they’ll sell and usually there won’t be any questions about harvest. If there are a lot of damaged beans, that’s when they start to ask about how they were harvested.

Time and Tillage Part II

Most of the information I’ve gleaned about time saved using reduced tillage has come from growers. In general the consensus is that reduced tillage saves both time and fuel. These two factors are cited as the primary reason that reduced tillage is a profitable alternative to conventional tillage.

Last week at the New York State dry bean meeting several growers mentioned that the amount of time saved with reduced tillage made the system worthwhile. One fellow who had switched to reduced tillage several years ago remarked that he spent less time tilling and was able to finish field work during the day light hours, or in to paraphrase his words: you spend less time banging around in the fields after dark. He also mentioned that equipment lasted longer and he needed less horsepower. To make use of the tractors he had left from conventional tillage he had just bought a 30 foot grain drill (used). Here’s another interesting point. The grain drill in question came from Ohio and with freight it was still cheaper than a new 15 foot drill in New York. Used equipment if it has been properly maintained can be quite a deal.

Another component of reduced tillage we aren’t able to measure at the research level is equipment maintenance. Reduced tillage typically requires less machinery than conventional tillage. When compared to conventional tillage the maintenance requirements and costs of maintenance are typically lower for reduced tillage implements.

Time and Tillage

Time saved as a result of reduced tillage is one of the factors we have difficulty measuring in a research setting. This is due to the small size of the research used in our studies, most plots are less than an acre in size. For example a tillage treatment might be 300 ft long and 50 feet wide. The small plot size means that we spend a lot of time turning around. The picture below shows some research plots. Its a bit hard to tell the scale of the plots (75' x 40') but it is possible to see the small area devoted to each crop, dry beans towards the front followed by sweet corn.

Experimental design can complicate matters even more. Components of an experiment are typically assigned at random; this increases the amount of time for field work. For example tillage treatments might be assigned like this: Conventional tillage, Deep Zone Tillage, Chisel Plow, and Zone Tillage in one replicate. In the next replicate the order might be: Deep Zone Tillage, Zone Tillage, Chisel Plow, and Conventional Tillage. To till the deep zone tillage treatments I’d have to till the first plot, then skip two plots to till the second area. The other three tillage treatments would be the same. As a result a lot of extra time would be spent driving to till a small area.

Now let’s consider commercial production, say a 40 acre field. If this field was exactly square (1320 ft x 1320 ft) a person could then drive for roughly that distance without having to turn around. Or if the field was rectangular say 500 ft wide by 3,500 ft long then it would be possible to till more area with less time spent on turning around.

The amount of time spent on field operations is also influenced by the size of equipment the larger the implement (plow, zone builder, strip builder, grain drill, planter, cultivator, combine etc.) the more surface area covered in one pass. There is a disadvantage to this (besides cost) and it is larger equipment typically takes more time to turn around. It wouldn’t make a whole lot of sense for me to use a twelve row zone builder if my biggest field was only 10 acres. This would be a bit like buying a semi (tractor trailer) to drive to the grocery store. Sure I’d have plenty of space for the week’s groceries but realistically I’d never need all that space and horsepower.

2008 Dry Bean Meeting

On Thursday March 13^th the annual New York State Dry Bean Meeting was held in Farmington NY. A major theme was the high bean prices, growers were getting around $0.40/b for light red kidneys. This price is considerably better than the $0.18/lb seen in years previous. Prices for other types of beans such as black turtle soups and dark red kidneys were also up from previous years. From what I understood light red kidneys commanded the best price.

The prices for other commodities especially wheat, which has been in the news lately, are also up. Part of this is probably a result of acreage being planted with grain corn for ethanol. As a result for acreage of the other crops diminished.

A major problem that has resulted from the increased corn acreage is a lack of seed. Seed for cover crops like winter rye is expensive or not available. This is also the case with bean seed. Every year there has been some contention about the availability of seed, but this year might be more serious.

What happened? Well, the bean acreage has been declining, and seed growers haven’t been able to sell their seed. The seed growers noticed the rise in bean prices and dumped their excess seed onto the food market and planted fewer acres of seed last year. It doesn’t make sense to keep planting something that isn’t selling.

The verdict is still out on if there will be enough seed. I’ve heard the answer is yes, there will be enough but it will be a close. The message was order seed early.

Remlinger Strip Builder

Another manufacturer of reduced tillage equipment is Remlinger, also located in Kalida, Ohio (the same city as Unverferth). The configuration of Remlinger and Unverferth tillage implements looks sort of similar at first glance. Both implements usually have a cutting coulter preceding the shank followed by paired coulters and rolling baskets.

There are several differences in the Remlinger machines though. The implements I’ve seen have a pair of row cleaners in front of the cutting coulter. The shanks on the Remlingers tend to be shorter, hence the name “Precision Strip Till row unit (PST)” or “Strip Builder” assigned by Remlinger. The pictures below are of a Remlinger implements; see Monday’s post for an example of an Unverferth.

It’s a little easier to see what the rolling baskets look like in the bottom picture. Different types of rolling baskets are available depending on the application and manufacturer of the equipment.

How do the two units compare? I’ve only had experience operating an Unverferth zone builder, so I’m not sure how they match up from an operational standpoint. From what I’ve heard the Unverferth zone builders tend hold up better in rocky soil. While visiting a couple farms this summer the Remlinger name came up in conversation and someone mentioned that Remlingers typically don’t hold up well when compared to an Unverferth.

A bit later we stopped at another farm where they used a Remlinger for strip tillage. In this case the grower said the Remlinger held up fine and he was happy with its performance. So what’s the deal here? Is it just a matter of opinion? Well possibly, but I left out a major detail, the soil difference between the two farms. At the first farm the soil was fairly rocky in comparison to the sandier soils I saw at the second farm. So perceptions of how a piece of tillage equipment holds up might be influenced by the soil type. This would explain why I’ve seen more zone builders in use on the rocky soils found throughout New York State.

Zone Builders

Unverferth Zone Builders are a common sight on farms using a form of strip or zone tillage. The smallest model I’ve seen is the two row model used for research purposes, that aside I’ve seen four to twelve row units in use throughout New York State. The size of these implements is due in part to size of the farm fields, which in turn is influenced by the surrounding landscape. In the hilly region of eastern New York, fields and equipment tend to be smaller. In western New York there are fewer hills; fields and equipment are typically larger. A four row zone builder is pictured below.


Most of the zone builders I’ve seen in use have a coulter to cut through surface residue, a shank, two fluted coulters, and a rolling basket in each gang. In this case a gang means all the things that till one area; the zone builder above has four gangs. The necessity of the rolling baskets is debatable. In heavier soils I’ve heard reports of them clogging or not really breaking up the clods. On lighter soils they seem to do decent job preparing the seedbed. I’ve seen cultipacker wheels substituted for rolling baskets and according to the grower who came up with the idea the set up worked great on the heavier soils in his fields. Unfortunately I don’t have a picture of this, but what grower did is take the rolling baskets off and used the frame to mount the cultipacker wheels.

Zone Tillage?

You’ll often hear strip and deep zone tillage referred to as “zone tillage.” For something to be considered zone tillage in the traditional sense the tillage would be accomplished using a series of coulters. The coulters are positioned in front of a planter or can be attached to a toolbar and used as a separate implement. These coulters are usually arranged in a staggered fashion and ideally spaced about 2-3 inches apart.

In my experience three fluted coulters seem to provide the optimal amount of tillage. This arrangement creates a nice grinding action which breaks up soil clods. As a side note it’s really interesting to walk behind the tractor and watch the coulters work. Watching the coulters work while driving the tractor is fun too, except the rows don't allways turn out straight.

Click on the movie below to see an example how zone tillage works. It’s a little hard to see the grinding action due to the camera angle and that the soil was a bit wet.

Why then is zone tillage used as a synonym to strip and deep zone tillage? I’m not entirely sure why, but here are some of my thoughts on the matter. Part of the difference is probably regional. Another factor might be that zone tillage is sometimes coupled with deep ripping.

In my opinion the brand name of a certain piece of tillage equipment, the Unverferth Zone Builder, might have something to do with it. From what I’ve heard it seems that the definition of zone tillage is changing to mean: tillage with 2-3 coulters or tillage using an implement configured like the one seen below.

To eliminate potential confusion in writing and talking about experiments here is how I like to define these three types of tillage.

Zone Tillage: tillage with three coulters.
Strip Tillage: tillage with a shank to a depth of about 10-12 inches.
Deep Zone Tillage: tillage with a shank to a depth of greater than 12 inches.

What Is Strip Tillage?

How do you decide if a tillage practice is strip or deep zone tillage? Basically it comes down to the depth of soil disturbance. Strip tillage disturbs the soil to a depth of about 10-12 inches. If the depth of soil disturbance is greater than 12 inches, then the tillage method is classified as deep zone tillage.

Depth of disturbance is only a basic guideline, another important factor is the way the soil is disturbed. This is probably most apparent in strip tillage where tilled strips can be prepared using a rotary tiller or a shank. A rotary tiller is basically a series of blades that spin really fast (roughly 1,540 rpm). The result of this turning action is a very fine seed bed, or a soil that has been pulverized. I refer to this type of tillage as “rotary strip tillage.” A shank (sometimes referred to as a ripper) is basically a narrow piece of steel that acts to fracture the soil profile. The picture below gives a nice example of what a shank looks like
The implement in the picture above is capable of tilling eight rows in one pass.

The number of rows you can till basically depends on the depth of tillage and available horsepower. If you have a bigger tractor you can pull a bigger implement (that tills more rows at a time) and it takes less time to cover more acreage. Hence the dramatic increase in tractor size and horsepower during the last 50 years.

Tillage using only a shank usually creates a rough seedbed. To further smooth the seedbed other parts such as rolling baskets, disks, coulters, etc. are often added to strip tillage implements. The picture below shows an example of such a set up. The exact configuration and components vary depending on manufacture, soil type, and grower ingenuity.

What is Conservation Tillage?

The actual definition of conservation tillage can be difficult to figure out. Conservation tillage practices typically result in a much lower level of soil disturbance. The picture on the right shows a field that has been tilled using a method of conservation tillage. Notice how the soil is disturbed in narrow bands or strips, leaving most of the surface residue in place.

Many times you'll hear conservation tillage referred to as "modified no-till" or "reduced tillage." Both of these definitions are pretty much correct, reduced tillage is usually defined as a method of soil preparation that decreases the amount of tillage operations or decreases the amount of energy used.

No-till as the name implies, is a cultural practice where very little or no tillage is performed prior to planting. There is some disagreement about whether no-till really is the complete elimination of tillage. To plant the seed some amount of soil disturbance has to happen. But compared to conventional tillage and conservation tillage the amount of soil disturbed in a no-till field is a lot lower. No-till production systems have been modified by tilling or disturbing narrow areas, hence the name modified no-till. For the sake of clarity I typically refer to these methods of soil preparation as reduced or conservation tillage.