August 6, 2024. Atypical weather in northern New York may have impacted field trials investigating the interseeding of alternative forages on corn silage yield and quality. The trials were conducted by Miner Institute with funding from the Northern New York Agricultural Development Program (NNYADP).
“We planted a trial in 2023 to investigate whether interseeding alternative forages into corn silage under northern New York growing conditions could be a way to improve the economics of interseeding by adding yield or quality value to the silage,” says project leader Allen Wilder, forage agronomist at Miner Institute, Chazy, New York.
The 2023 growing season in northern New York was not typical for the region. Conditions were abnormally dry in the spring, followed by an anomalously wet summer. The spring and fall were warmer than normal; however, there were notable cold spells in May that delayed crop development. Late summer was slightly cooler than average. A warmer-than-typical fall in northern New York extended the growing season and contributed to an extremely rapid dry-down. The total yearly precipitation recorded at Miner Institute in 2023 was 142.7 percent of normal.
Wilder established trials at Miner Institute in Chazy, New York, and at a working farm in Mooers, New York. At both sites, corn was planted on 30-inch rows at a plant population of 32,019 plants per acre. Previous manure application provided most of the crop nutrition during the growing season. Glyphosate alone was used for weed control.
Male sterile forage sorghum and forage kale were selected as the alternative forage crops for the trial.
Interseeding was done at the V5 stage of a dwarf variety of corn at Chazy and at V7 stage at Mooers with a six-row drill interseeder. Seeding rate was calculated to be approximately 10.7 pounds per acre for the sorghum and 6.4 pound per acre for the kale.
At the Mooers farm, the interseeding was done relatively close to corn canopy closure, thus, Wilder says, “It is not surprising that no statistical yield difference was detected in the corn there. Almost all the kale had completely died out by the end of the season as a result of being smothered by the corn.”
The forage sorghum at the Mooers site did not reach a height sufficient to be even partially harvested with the corn.
An earlier interseeding date – June 16th at Chazy vs. June 30th at Mooers – plus the shorter stature of the dwarf corn likely helped the establishment of the interseeded crops at Chazy. By the end of the season, the sorghum, waist high in some areas, produced harvestable biomass able to be cut by a multi-directional corn head. The kale, however, appeared stunted and was unharvestable.
“The interseeding at Chazy of corn with forage sorghum and kale did not result in a corn yield decline. Oddly enough, the moisture content of the corn interseeded with kale was affected with the kale causing the forage sample to be slightly drier than that of the corn interseeded with forage sorghum and the corn-only control,” Wilder says.
Significant differences were not detected in forage quality at Chazy for most parameters evaluated, with some exceptions.
Forage samples from both the interseeded kale and interseeded sorghum plots were proportionally lower in protein than the corn-only control. Wilder says, “This may be a symptom of increased nitrogen demand on the soil of two crops growing at the same time. In this case, it would make sense that the nitrogen would have to be split between the crops and a lower total crude protein percentage would be harvested.”
Crude fat was slightly, but significantly, lower from the kale interseeding. Wilder postulates that interseeding reduced the fat content of the corn, while additional lipids were captured in the sorghum treatment through harvesting of the sorghum tops.
This one-year trial suggests interseeding at V5 stage or earlier may be warranted for growers in the state’s northern region; however, this single trial also evidences the need for more evaluation of the performance of corn interseeded with alternative forages under different years’ growing conditions. More data would also help with the important selection of forage species for best results with interseeding.
The results of these trials conducted by Miner Institute with funding from the Northern New York Agricultural Development Program are publicly accessible at www.nnyagdev.org under About: NNYADP Projects by Year: 2023.
Funding for the Northern New York Agricultural Development Program is supported by the New York State Legislature through the New York State Assembly and administrated by the NYS Department of Agriculture and Markets.
Click here to see the Plattsburgh Press-Republican story on this research.