The first year of a three-year corn silage study in Saskatchewan showed a trend toward yield differences between two seed brands across the province’s corn heat unit (CHU) zones.
“One brand out-yielded the other in short-season zones and the other brand had the best yields in the longer-season zones,” says Dr. Joy Agnew, project manager with the Prairie Agricultural Machinery Institute at Humboldt.
This project is reviewing nitrogen application rates and taking a closer look at seeding rates at two sites in each of three distinct CHU zones from Melfort in the north to Redvers in the south. The Saskatchewan map of average CHUs for silage production shows that the Redvers area receives 2400-2500 CHU from May 15 to the first killing frost (-3 C), whereas, Melfort averages 2100-2200.
DuPont Pioneer and Monsanto selected a hybrid for the short-season (northern) sites and a hybrid for the long-season (southern) sites. This year, each seed supplier provided a short-season, mid-season, and long-season hybrid.
The typical seeding rate of 100,000 seeds per hectare is being compared to a low seeding rate of 75,000 seeds per hectare and a high seeding rate of 125,000 seeds per hectare on 30-inch row spacings with a SeedHawk corn planter, giving in-row plant spacings of 10, seven and four inches.
“There was no yield difference between the low- and mid-seeding rate, but there was a trend to higher yield at the high rate compared to the medium rate. It may make sense to go with a higher rate if your goal is to get yield,” Agnew suggests.
Nitrogen was applied at low, mid- and high rates of 100, 150 and 200 pounds actual N per acre, respectively. As expected, more nitrogen produced more yield; however, going to the high rate did not result in significantly more yield than the mid-rate.
The final report will also include feed quality results and a detailed economic analysis of production costs in the various CHU zones to help beef producers decide on seed choices and agronomic practices to make the most of their investment in hybrid corn seed and fertilizer for silage corn.