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The Crop Masters direct seeding project was established to look at some of the agronomic concerns we had with direct seeding. Those concerns included: is the soil colder? Would we conserver any moisture? Would the quality of the grain change? Would it work on our soils here at home?
In an attempt to answer these questions, a project was initiated where several cooperators split a field in half, with half the field seeded the way the producer currently seeded and the other half seeded with a direct seeding drill. Over the course of the growing season we tried to measure any differences between the "conventionally seeded crop" and the "direct seeded cop". We attempted to measure differences in solid temperature, soil moisture, germination, weed populations, yield and grain grades. The project ran for four years, from 1993 to 1996 and crops seeded included wheat, barley, canola and peas. This article discusses what we found.
NOTE: It is very important to keep in mind as one reads this article that the terms used for comparison are "direct" and "conventional", but the term "conventional" is used very loosely and is almost inappropriate at this time. The majority of the "conventional" seeding taking place by the cooperators is done with air seeders, utilizing a 3, 3 and in some cases a 1 pass system, therefore a more descriptive term would be minimum tillage. A reduction in the number of passes was seen by many producers as the project progressed because producers became more comfortable with minimum tillage. However, when we started the project we described the producers' seeding system as "conventional" so we continued to describe it as such.
EQUIPMENT: Each year we leased a direct seeding drill and each year we tried a different manufacture to experience drills with different features. The following are the direct seeding drills we used and some of their specifications.
1993 - Flexi-Coil 5000 Air Drill - 9" spacing, stealth double shoot opener, 2 1/2" steel "v" packers.
1994 - Morris Maxim Air Drill - 7" spacing, double shoot opener which places seed 1" above and 1" to the side of the fertilizer band, 3" steel packer.
1995 - John Deere TV - 12" centers, TV opener, 4" seed spread width, double shoot, shank mounted packer.
1996 - Conserva-Pak - The drill was equipped with 12" row spacing and equipped to band dry and anhydrous fertilizers. The features of the drill is it uses a narrow knife opener to place the seed and all the fertilizer in one pass. The depth position of the seed opener is controlled by the packer which follows only inches behind to provide on-row packing with adjustable pressure.
SOIL TEMPERATURE: The common though is that the soil is cooler when direct seeding. Soil temperature was measured at 5 depths from the date of seeding to the 2 leaf stage of the crop. This was only done on one field because the equipment and the time needed to take these measurements for 2 years and could not find any substantial differences. Most studies have found that under direct seeding the soil temperature is cooler by 1-2 degrees because of the increased moisture content and crop residue. However, they are finding that if the soil is disturbed the soil warms up quickly to show no difference in soil temperature. This may be what we found because all the seeding tools we used were hoe-type openers that created a fair amount of disturbance.
SOIL MOISTURE: With direct seeding we should be able to conserve seedbed moisture. We measured soil moisture on 3 cooperator fields for 3 years. Several cores were taken with the % of water content determined. The data collected showed no significant differences in moisture content between direct and conventional, however, the direct side showed slightly more moisture in some cases. Increased soil moisture conservation was evident when we measured the crop yield in 1995, the year of extreme drought, where direct out yielded conventional in all cases, but was not conclusively exhibited in out soil water content sampling.
GERMINATION: The germination, or plant populations were counted shortly after emergence to give an indication of how well direct seeding prepares the seedbed for plant germination. The concern was that direct seeding may reduce or delay germination. No real significant differences were noted, but in some cases the conventional side exhibited a slightly higher germination rate. Canola is the most sensitive crop in this situation because of its small seed size. The opener on the drill must do a good job of placing the canola seed into the firm, moist seedbed for a satisfactory plant stand to establish, the consequence is a very weedy field.
WEED POPULATIONS: Many believe that the weed spectrum changes when direct seeding and fields that are direct seeded contain more weeds. We counted weeds twice, the first time after crop emergence and the second time was late into he season to see if any perennial weeds would be increasing. The first weed count showed that the conventionally seeded crop usually contained more volunteers and stinkweed. The second weed count was variable, with some cases showing more weeds on one side than the other. It is very important to note that when direct seeding, the pre-seeding burn off with Roundup is crucial and it is better to do it before the weeds get too big. If weeds are sprayed when large, their "carcasses" tend to interfere with the direct drill's openers, therefore it can affect the seedbed.
YIELD AND QUALITY: This is the most important measurement of all. A difference in yield or quality will also tell us if the agronomic factors we attempted to measure really are having any impact on the crop. We measured yield by using the cooperator's combine and a weigh wagon (hopper scale). The graphs in this document show the differences in yield between direct and conventional at each cooperator site.
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Overall, during most years and in most cases the conclusion can be drawn that little or no difference in yield exists. However, a difference in yield definitely existed in 1995, the year drought was extreme. In that year, all cases demonstrated that the direct seeded crop yielded higher than the conventionally seeded crop. Samples of grain for grading were taken when the yields were being determined to see if direct seeding affected the grade. It was hypothesized that direct seeding may delay maturity therefore affecting grade and/or weight or there may be extra weed seeds which would increase dockage. Overall very little difference existed between the two samples. The actual grad e of the crop never changed when comparing a direct seeded crop to the conventional.
ECONOMICS: The economics of direct seeding are frequently related to the discussion of "direct seeding". There are 4 main areas where the input costs of direct seeding will be different from conventional seeding, these being fuel and repair costs, labour costs, herbicide costs and machinery ownership costs.
When direct seeding your fuel and repair costs should decrease because you will be making fewer passes. Labour costs should decrease for the same reason, a farm that does not hire labour will see minimal savings, but a farm that does hire labour would see a substantial savings. Herbicide costs for direct seeding may be slightly higher because of the cost of the pre-seeding burn off. Your machinery ownership costs should decrease when direct seeding because you require fewer tillage tools, but this is a long term savings and many producers find that they still retain their tillage tools, "just in case".
To summarize a study done by Terry Appleby of Alberta Agriculture Food and Rural Development for producers in Alberta, he calculated the cost savings of direct seeding at $2.60 per acre.
Overall, no difference in crop production was observed between conventional seeding vs. direct seeding. The only year that showed a difference was 1995, but this year was an extreme deviance from normal. As a result of this information, many producers are currently direct seeding. From our club, out of 15 members, 7 members are actively direct seeding all of their crops, and the balance are very comfortable with the concept of direct seeding.
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