2012 - a banner year for cover crops

Thursday, January 3, 2013

Special circumstances set us up for the largest seeding of cover crops ever in Ontario. They're good for the soil, help increase yields for subsequent crops and sometimes can even be sold

by PAT LYNCH

There is an adage which holds that "good things can come from bad things" or something like that. This past year, there was a lot of bad associated with forages in Ontario. Supply was short. Fewer acres were seeded in 2011 than normal. Some stands thinned over winter due to old age. Then drought across North America greatly decreased forage supply.

These events set us up for the largest seeding of cover crops ever in Ontario. In 2012, 280,000 acres of red clover were probably seeded and another 100,000 or so of oats and oat mixtures. Then a bunch of acres were seeded to species like oil seed radish and soybeans. Many of these cover crop acres were sold for forage. The concept of cover crops for the sake of a cover crop never took off. But if there is an immediate profit in growing cover crops, they become more attractive.

The most exciting of these were the acres seeded to oats or oat mixtures. This is a new-old crop and a lot of experience was gained with it this year. Summer seeding of oats is not new. I have read about it in government publications from the 1950s when it was harvested more as pasture.

The results this year were not unexpected. Oats grow well in August and September if you get a minimal amount of rain. But it is easier to grow this crop than to harvest it. I heard horror stories this year of oats being swathed and then rotting in the swath before they could be harvested.

Rule number one. If you are trying to make stored feed with oats in October or later you must swath it wide and use a merger. You have to be able to cut and harvest it in 24 hours. And then it either goes into a silo or is wrapped.

Oats use nutrients, so rule number two is that you need a minimum of 40 pounds per acre of nitrogen either as fertilizer or manure. Producers using manure and getting more than 40 pounds per acre of nitrogen had higher yields than those using fertilizer and 40 pounds of nitrogen.

In fact, I think we should be applying closer to 60 pounds per acre of nitrogen. And oats or mixtures with oats remove a lot of P and K. It was not uncommon to get three to five big bales of the various mixtures in 2012. This is 2.5 to 4.25 tons of dry hay. These rates remove about 40 to 60 pounds of phosphorus and 90 to 120 pounds of potassium. At current fertilizer values, that is between $50 and $70 per acre of P and K plus nitrogen. There is probably two to three cents worth of fertilizer per pound of dry forage in these cover crops mixes.

Oats cut in October are low in protein. This means the places where they can be used are limited. If you cut early at the boot stage, you can increase protein to 16 per cent or higher, but yield will be lower. Producers who added peas to this mix were able to increase the protein levels.

There have also been complaints that the feed value is variable. Those comments are real. But if it is planted, managed and harvested all the same there is little variation in feed value.

In Ontario we have struggled to get producers to plant a cover crop. This year, due to special circumstances, there was an opportunity to plant a cover crop and sell it for profit. Will this trend endure?

I hope so. We need more acres of cover crops. There are at least three months of good crop growing weather after winter wheat and some spring cereals when we should have cover crops growing. They will protect the soil, build soil texture, control weeds and reduce erosion, all of which will increase yields of subsequent crops. And sometimes you can sell this crop.

According to Statistics Canada, there were roughly 750,000 acres removed from hay and pasture between 2006 and 2011. That was our reserve of forages for bad times. The use of cover crops will help fill that void. And if there is no market for your crop, you will still have the benefits of a good cover crop. BF

Consulting agronomist Pat Lynch, CCA (ON), formerly worked with the Ontario agriculture ministry and with Cargill.