The case for growing more forage crops
Monday, December 3, 2012
Cover crops for forages are a huge untapped resource in Ontario. With shortages expected in 2013 and maybe 2014, don't just think about planting more. Do it
by PAT LYNCH
The forage shortage in 2012 will continue for 2013 and maybe into 2014. That means you need more forages from every acre you crop.
If you have thin stands that were seeded in 2012, you can do something about it. They will not thicken by themselves. While alfalfa has hard seeds, all the alfalfa seeds that are going to germinate do so in the first 30 days. This is different from hard seeds in clover that may germinate years later.
In areas with less than six to eight plants per square foot, work the soil lightly next spring and plant again. It is not good enough to broadcast. Consider using a nurse crop for weed control and forage volume. You do not have to worry about auto-toxicity in fields planted in 2012.
If you want to thicken a stand in areas too small to work, broadcast red clover and timothy in March. You and others may think alfalfa will establish if broadcast into established alfalfa. Think again. It has been tried enough times to say it won't work.
Another thing that didn't work in 2012, and seldom does, is taking a first cut of alfalfa and no-tilling corn into the field. Between conditions that were too dry, too many volunteer alfalfa plants and planting late, the odds are you will be disappointed. A better bet is to work the land in the spring and plant a full-season corn silage hybrid. You will get more feed that way than by taking a first cut and planting corn afterward. You will gain in excess of 30 bushels per acre of corn or four to five tons per acre of silage working and planting early.
Fertilize all existing forage stands. A four-to-five-ton per acre alfalfa crop removes 60 to 70 pounds per acre of phosphorus and 250 to 300 pounds per acre of potassium. You need to apply 10,000 gallons of liquid dairy manure per acre to return this much P and K.
Alfalfa responds to sulphur. All the talk of sulphur on wheat and corn also applies to alfalfa. In fact, alfalfa needs more sulphur than wheat or corn. Fields most prone to sulphur deficiency have lighter soils and older stands or were in corn silage. Manure is a significant source of sulphur. You should apply about 20 pounds per acre of sulphur after the first cut to maximize forage yield. Alfalfa also responds to boron. Some growers are adding one pound of boron after the first cut.
In 2012, forage insects took a big bite out of forage yields, with new seedings being hurt the worst.
All new seedings should be checked for insects after the first cut and most may benefit from measures to control insects. U.S. research indicates that if leaf hoppers become a serious threat in the year of establishment and are not controlled, this will affect forage yields in succeeding years.
An easy way to increase forage yields is to leave the field down for fewer years. Forage fields in their third year yield at least 13 per cent less than fields in their second year. Would you keep a cow that produced 13 per cent less milk than the rest? Would you plant a corn hybrid that you know will yield 13 per cent less than the rest of the hybrids? So why leave forage stands down so long?
Take a long look at harvesting cover crops for forages. There are at least 1.5 million acres of land in Ontario that could grow cover crop for forage. There may have been 350,000 acres of cover crops grown in 2012. That leaves over one million acres that could grow a cover crop for forage.
In 2012, the average forage yield of cover crops was about two tons per acre. Statistics from the Ontario agriculture ministry report that the average forage yield from hay crops in Ontario is 2.5 tons per acre. Cover crops for forages are a huge untapped resource. If you need more forage in 2013, grow a forage cover crop. Don't just think about it. Do it. BF
Consulting agronomist Pat Lynch, CCA (ON) formerly worked with the Ontario agriculture ministry and with Cargill.