Seed is the highest input cost for soybean growers. It is important that a grower achieves a targeted plant population so that input costs can be minimized while maintaining top yield potential.
There are numerous well documented factors that can effect soybean seed survival. The purpose of this study is to develop % seed survival guidelines to assist SeedMaster NovaXP owners in targeting precise soybean plant populations.
This study also compares how tillage and direct seed practices can effect seed survival.
SeedMaster operates a 2000 acre research and development farm located in SE Saskatchewan. The soil is classified as a Black Chernozemic soil. Topography is categorized as gently to moderately rolling. Organic matter ranges from 3.8 to 4.9% with a ph of 6.9 – 8.0 on average.
The SeedMaster Research farm has access to a 100-15-SXX-20 with a tow behind 820NovaXP. It is a 100’ wide toolbar with 80 openers on 15” row spacing. The toolbar houses a front mount 20bu on-frame tank that features individual row metering (IRM). The 820NovaXP is a tow behind air seeder comprising of 4 compartments. 3 – 260bu tanks and 1 – 40bu tank. A John Deere 9630 tractor is used to pull the implement. A Viper Pro monitor controls drill/tank functions plus tractor guidance at RTK correction level.
On May 28th, 2014, a Salford 5100 vertical tillage implement was rented from a local source at a single day cost of $1653.75. The tillage machine was connected to the John Deere 9630 tractor and a single pass was completed on 25 acres of a 140 acre wheat stubble field. Approximately 4 – 6” of soil was displaced by the tool, leaving a black seed bed that comprised of loose soil with little wheat residue on the surface.
Seeding commenced 2 days later on May 30, 2014. There is plenty of literature available that stresses to wait until the average soil temperature has warmed up to at least 10° C, (18 - 22° C is ideal) before commencing seeding operations. Below are the documented soil temperatures at the approximate ¾” seed depth.
The no-till stubble averaged 25 degrees Celsius (77 degrees Fahrenheit), while the tilled stubble averaged 29 degrees Celsius (84 degrees Fahrenheit), just prior to seeding.
MAP 11-52-0 was applied from the front 260bu NovaXP tank at a constant rate of 50 lbs/acre directed through the fertilizer knife. Placement was at the SeedMaster factory setting of 0.75” below the seed and 1.50” to the side of the seed.
TagTeam granular inoculant was applied from the 40bu NovaXP tank at a rate of 3.1 lbs/acre. It was directed through the seed knife.
Legend LS002R23 soybean seed was used for the trial. The seed was treated by the retailer with Cruiser Maxx® Vibrance™ Beans and Nodulator® N/T soybean inoculant at the recommended rates. The seed germination was assessed at 94%. TKW of the soybean seed was 158.4 g/1000 seeds. Soybean seed was loaded into the most rearward mounted 260 bu tank on the NovaXP cart using the attached fast-fill conveyor. Soybean seed was directed through the seed knife.
Seeding commenced on May 20th 2013 in the early afternoon.
On June 30rd 2014, plant counts were completed using a hula hoop to determine average plant populations for the tilled and direct seeded portion of the field. Below are the results.
Overall, the tilled and no-till treatments had a very similar seed survival. I believe this is due to the soil temperature being quite high at the time of seeding for both treatments. If we had completed the trial earlier in the spring as originally planned, before soil temperatures has risen well above 10 degrees Celsius, it may have shown an effect on seed survival between the two treatments. Although, it is thought that the black strip of soil left behind the SeedMaster opener will aid greatly in increasing the soil temperature after seeding has been completed and negate any advantages of tillage.
The same trial will be completed in the spring of 2015 on the SeedMaster Research Farm. Soil temperature will be monitored to determine time to plant. It will be the goal to complete seeding as early in the season as possible to increase overall plant height, increase height of the lowest pods, maximize daylight and most of all… help alleviate later season frost risk.
These results will vary in subsequent trials, depending on environmental conditions present at seeding time.
This trial should be repeated in time and multiple locations across a broad geography.
Special thanks to the following:
Delmar Commodities Ltd. - Maik Kort - Seed Division/Agronomy
Richardson Pioneer Ltd – Whitewood, Saskatchewan