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14 years of experience with zero till

When I started farming in 1986 I adopted my father’s techniques. Like most beginning farmers, I took a job to help pay for my farm. I became the soil conservation technician with what was then I.D. #22 Applied Research Association in Manning, Alberta.

My job included looking at the potential for farmers in the Peace River region to adopt zero-till seeding. After seeing the results of zero till trials we conducted in 1990-91, I bought a zero-till drill and converted my own farm to zero till in 1992. In 2011 I celebrated my twentieth year of zero till — this outlasted my marriage! I see no reason why this will change.

Because this has been a long experiment, we’ve generated a lot of information. This article covers our yield results over the 14-year period, and some of the agronomics we noticed in the first few years. In the next issue of Grainews, I’ll cover the longer-term changes measured in the soil after several years of zero till.

Converting to zero till

My conversion to zero till was fairly straightforward — I looked at the results of the trials I was involved with in 1990 and 1991 and saw that in each case, yields were equal or higher than with conventional till. With higher yields and less work, why not adopt this system? But other farmers I was worked with did not share my view. Why?

I believe it came down to confidence and risk. After two year of trials, I accepted zero till as a viable system. Other farmers didn’t want to take the risk. I couldn’t argue — two years isn’t enough to be sure that the system worked over the long term.

During my employment and zero-till trials I got to know Otto Toerper. Toerper, along with his wife Inge, ran a mixed farm about 15 miles south-west of Spirit River, Alta. He had been participating in a conservation seeding trial since about 1988. We decided that we would study three different seeding systems: conventional till (two or more spring tillage passes), minimum till (only one spring tillage pass) and zero till (no tillage passes, weed control with 0.5 litres per acre Roundup burn-off herbicide).

The entire plot area covered 20 acres, with each of the nine strips being a little over two acres each.

I knew it would be essential to gather information like this for as long as possible. The more data I had, the stronger the case for selecting one tillage system over the others. This would make farmers more confident about making changes.

First-hand experience can be a very powerful a teacher. Toerper was very generous with his time and understood the benefits of long-term plot information.

Tillage comparisons

When I first started the tillage comparisons with Toerper I really had no idea where it would lead. Most of my previous plot work with farmers lasted two or three years. Then they adopted the new management practice and the plot was stopped.

But this was a rare thing. This plot has been in use since 1994. The final year I was able to use the site was in 2007. This means we have results going back over 14 years, although some years we were not lucky enough to collect data. In 2003 the snow fell early and the plot could not be combined. In 2004 it rained heavily enough that I was only able to weigh one of my plots out of some 25.

Long-term test data serves will strengthen our confidence, and providing that data is purpose of my work. Having a long-term project like the “Toerper Tillage Trial” is one of the reasons why I have the confidence in recommending zero till. This is not based on a few years of work, and it’s a pleasure to share the results.

We’ve seeded four different crops — canola, hard red spring wheat, feed barley and field peas. We’ve seeded through years of double normal rainfall, years when there was half normal rainfall and even a year when there was frost in August.

In 1994, a Flexi-Coil 5000 air drill was used to seed the plot, while from 1995 to 2007, we seeded the plot with a Haybuster 8000 zero-till drill. The minimum and conventional tillage systems reflect normal operations for the area. The zero-till system was normally sprayed with 0.5 litres per acre of Roundup. Sometimes the tillage strips were sprayed as well (like in 1995) to help control weeds like quackgrass.

Damage and heat banding

In 1994, Year 1, we learned there were some immediate benefits to growing crops under a zero-till system. 1994 was a hot, dry, windy spring. I looked in a number of fields that had been tilled in the spring and I saw a remarkable sight: the newly emerging plant leaves were severely damaged. At first, I suspected insect damage, but after having to cover my face to prevent dirt blown in my eyes, the answer came to me. The leaves were damaged by particles of loose soil being propelled across the soil surface. These particles would strike the leaf surface like a sand blaster. Small pieces of leaf were getting broken off! I was so excited by this sight that I drove to Toerpers’s field. In areas that had been tilled and I saw the same thing but the seedlings emerging in the zero-till land were fine. “Ah ha!” I cried. “Standing stubble really does protect the new crop from damage!”

As the crop continued to grow, I made another interesting observation. A number of the intact plant leaves had alternating bands of yellow and green. What was going on? As I crossed the field I started to notice a pattern. The leaves were only this pattern where the ground had been cultivated, but not in the zero-till area. Puzzled, I asked other extension people and was told this damage was called “heat banding.” It occurs when the maximum and minimum temperatures that a plant is exposed to vary a great deal (very cool in the morning and very hot in the afternoon) and the plants become stressed. I was stunned. Zero-till stubble was preventing the temperatures from getting too hot or too cold and protecting the plants from stress.

As shown in the table, after the first year of the trial, the crop grown on the zero-till land yielded eight bushels per acre more than the crops on minimum- and conventional-tilled land. This was after the first year of the trial.

Trafficability

In 1996 while we were seeding the plot, I noticed another difference between the seeding systems. I have heard of some zero-till farmers who talk about their land being easier to drive on — “better trafficability” they call it. Since time is money, we usually seed at a fairly rapid pace, up to five miles per hour. When it came to turning at the headland, the front wheels used to really dig into the soil on the minimum and conventional till strips and would throw up a “rooster tail” of soil. This never happened on the zero-till plots. Due to this better trafficability, the turning radius of the tractor on the zero till was less, and fewer passes were needed on the headland to finish the field. The benefits occur where you least suspect them sometimes.

Crop residue

By the time we were seeding in 2000, after six years, you could really start to see a nice layer of crop residue building up on the soil surface of the zero till. This difference was easiest to observe after seeding was completed. The surface of the minimum and conventional areas was barren of residue on the surface. While this might not seem too surprising considering that the previous crop was field pea, the zero till had a nice layer of residue to protect the soil and soon-to-be emerging crop.

Plant height

The wheat that was seeded into the pea stubble in 2000 was remarkable as well. As the summer wore on, I started to notice some strange differences along the boarders between the tillage treatments. As time went on these differences became more pronounced and warranted a closer look.

The most interesting point of all was that when I took crop height measurements and analyzed the data, the differences were significant. The zero-till crop both out-yielded the minimum and conventional tillage by three to six bushels per acre, and grew taller. The zero-till wheat was 39.4 centimetres; wheat in the conventional and minimum till strips were 34 and 35.2 cm. When you reached the edge of a zero-till strip, the crop just shot up in height!

Weeds and tillage

While the barley crop was growing during 1994, I began to notice something discouraging. The wild oat pressure was considerably higher on the zero till compared to the minimum and conventional till areas. While this bothered me at first, I tend to look that the bottom line. The net yield of the zero till was eight bu./ac. higher than the other areas. The question was, what would be the effect of these seeding systems on weeds in the long term?

I felt confident weeds such as wild oats would not be an issue for zero tillers. As time went on, I was to be proven correct. 2001 provided me with some of the strongest support on how long term zero till can result in fewer weed problems when competent management practices are carried out.

After seeding the plot to Roundup Ready canola, I came back to do the in-crop herbicide application. When I drove in the field, the first thought that came to my mind was what a nice crop of wheat this was. As I got closer I noticed that the zero-till areas were not as green. I was, at first, a bit disappointed but then the truth came to me. It wasn’t seeded to wheat, it was seeded to canola! All those lush green plants were actually weeds! I could not believe what I was seeing. My first thought was that the zero-till strips might not even need to be sprayed. Since this would have made the spraying operation more difficult I sprayed the entire plot in the end. The result? The zero-till canola yielded four bu/ac higher than the other canola!

This was not some little small trial seeded with some kind of off-brand name research drill. The drills used are drills that farmers can buy themselves. The environmental conditions we faced were common for our area, and this system works. It is not, after 10 years, just a case where we tried zero till for a year or two and got good results. We used good management practices, did not cut corners, and the end result? We made more money with zero till. †

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