FLAX STRAW MANAGEMENT: CHOPPING SaskFlax Web Article Series In Saskatchewan, producers plant 1.4 million acres to flax each year, about 70 % of Canada’s total production. Flax is considered a favourable addition to many farmers’ crop rotations—more than one in four Saskatchewan producers plant flax each year. However, an overwhelming constraint to flax production is dealing with flax straw residue.

Oilseed flax has a significant percentage of long tough stem fibres that decay slowly over time. This makes it difficult to incorporate flax straw into the soil after harvest since the fibres wrap themselves around and/or plug disks, wheels and shovels. In the past, one way to cope with flax straw was to drop it in windrows after the combine and then burn it directly or harrow or rake it into piles and then burn it. Today, this practise is discouraged for a number of reasons: because it is unsafe and can harm the soil; because the straw has economic value; and because of the damaging effect on air quality and human health.

To help raise awareness of alternatives to burning flax straw, the Saskatchewan Flax Development Commission (SFDC) is working with Agriculture & Agri-Food Canada on an Agri-Environmental Group Plan (AEGP) for straw management. Through this program, Saskatchewan flax producers, represented by SFDC, can work together on developing Beneficial Management Practises (BMPs) that will both improve air quality and enhance economic opportunities available to farmers.

In the first of a series on the Saskatchewan flax straw management AEGP, this article will discuss chopping as one option available to farmers for dealing with flax straw.

Chopping

In many cases, chopping and spreading flax straw is a viable and much preferred alternative to burning. To determine whether their straw is likely to chop easily, producers can conduct a simple test in the field. Select between 5-10 stalks of straw from the field, hold them with both hands and pull them rapidly apart. If the stalks snap, your chopper is likely to be able to deal with your flax straw; if the stalks resist breaking, you may want to find another use (instead of chopping) for your straw. Remember to check more than one spot in your field; your sloughs are likely to have the highest moisture content and tallest plants, which will make them the most difficult to chop.

There are three factors that have an impact on whether chopping will work for you.

1. Equipment

Straw choppers on the largest new combines have been used to effectively chop and spread flax straw, if the straw was relatively short. If straw can be sufficiently chopped and spread, it can be incorporated into the soil without causing too much difficulty for future crops. However, many farmers find it difficult to chop and spread flax straw because:

• Their straw choppers cannot handle long, tangled flax straw
• Their combines do not have enough power
• Their spreader or chopper cannot spread the straw in a thin enough and wide enough layer to make it easy to work through in spring
• They harvest flax late in the season when the straw is damp and hence stronger (flax straw is stronger as its moisture content rises)

Rotary combines are generally better for chopping flax straw than conventional ones. Of course, chopping effectiveness can be improved by sharpening the stationary blades or installing new hammers. Certain chopper/spreaders (i.e., Redekop Chopper/Blower) are more effective than others because they use a wider spread pattern, distributing the straw in a thinner layer over a wider area, and this allows the straw to more easily work into the soil in the spring.

Some producers utilize a forage chopper without the silage wagon to pick up the windrowed straw, and then chop and blow the residue onto the field.

2. Dessication

Another tactic to make it easier to chop flax straw is to spray flax with Roundup™ before swathing or combining. This causes the flax to dry out and break down somewhat, allowing the knives to cut through the straw more easily.

It is important to spray early enough that the plant is still partly green in order still be able to absorb the Roundup™ spray.

3. Conditions

Flax straw is easier to chop after a hot, dry day. If you’ve had a hot, dry August, and/or your crop is short, chopping is more likely to work efficiently for you. The more moisture still in the plant, the tougher it will be to break the stalks with the chopper.

It is very important for flax growers to test each year whether they can chop their flax straw, because so many variables will affect this. One year’s growing and harvest conditions are so different from the next that chopping may not be an option one year, but may work well the following year.

For more information, contact the Saskatchewan Flax Development Commission, at (306) 664-1901 or saskflax@saskflax.com .