Traditionally, seeding a forage crop has meant seeding a cover crop with it. Cover crops are used to protect the fragile forage seedlings from the blasts of the wind and reduce competition from weeds. And they provide a crop of sorts in the year the forage is establishing.
But the times they are a changin' and for producers interested in insuring maximum yield of their forage crop, cover crops are being omitted or seeded at a very reduced rate. While annual crop producers have long recognized the benefits of standing stubble to little seedlings, the principle is being applied to forage crops as well. With the standing stubble serving to protect the little seedlings from the forces of Nature, a cover crop isn't necessary. Standing stubble also ensures the forage seeds are being placed in a firm, moist seedbed, the number one requirement for successful forage establishment.
Implementing a weed control strategy before the forages are seeded is very important. Applying Roundup to the previous crop in the fall will control the perennial weeds and a healthy blast of Roundup in the spring takes care of the annual weeds prior to seeding.
But what about taking a crop in the year of establishment? It depends upon which side of the picture you look at says Brant Kirychuk, Head of Range Management with PFRA. "There is no question that a cover crop will drop the yield of the forage crop in subsequent years. From a true agronomic point of view, cover crops should be omitted." Cover crops tend to be more aggressive than the forage crops and, therefore, compete with the forages for moisture and nutrients. This is a particular concern in years of limited moisture.
Newfield Seeds in Nipawin has set up a non replicated plot where Meadow brome grass, Kentucky blue grass, Crested wheat grass, creeping red fescue, timothy, red clover and bird's foot trefoil were seeded. Seeded at right angles to the forages were oats, barley, peas, flax and both Argentine and Polish canolas. The control treatment had no cover crop seeded. Gord Pearse of Newfield Seeds said the results proved very interesting. "We evaluated establishment and ground cover rates", Pearse said. "Oats proved to be the worse cover crop although in the years we had the plot it was quite wet so there was a lot of lodging in the oats. Barley followed the oats in terms of limiting the establishment and ground cover of the forages. Polish canola was less competitive and flax worked well when it was sprayed out".
However, if you look at the economic point of view, Kirychuk says it's difficult to ignore the returns from a cover crop. "In the Black Soil Zone, many producers like to take off some green feed and either sell it or use it for their own livestock. They counter the reduction in yield of their forage crops by the value of the green feed".
Kirychuk recommends that producers in the Brown and Dark Brown Soil Zones and those who are growing forages for seed should not use a cover crop. Exceptions are those on heavy clay soils and those who wish to stabilize very light soils prior to the emergence of the forage seedlings. For those who are using forages for pasture and hayland in the Black Soil Zone, Kirychuk recommends that the seeding rate of the cover crop be dropped to 1/3 or 1/4 of the normal seeding rate and that the cover crop be cut early. "Decreasing the seeding rate of the cover crop and taking it as green feed will allow the producer to get some production in the year of establishment and enable the forage to recover from the competition before winter sets in".
With the growing interest in seeding forages in the East Central Region, we decided to design our summer plot tours around forage stand establishment. In one of the plots we've direct seeded alfalfa at 6 lbs per acre. Then we underseeded Pursuit Smart canola at 3 different rates . We'll be taking plant counts and doing visual assessments to determine the difference in the establishment of both the canola and the alfalfa.
In another plot, we direct seeded timothy into year old oat stubble. In this plot, we varied the seeding rate, seeding depth and fertilizer placement: side banded or seed placed.
A third plot has been seeded to a number of grass varieties. Seeded directly into standing barley stubble, the 7 grass varieties were cross seeded to various rates of oats. Various fertilizer treatments have also been applied to the plot.
The establishment of some of these plots is a co-operative effort between the Sask Soil Conservation Association and Sask Ag and Food. Sponsorship for the plots has been provided by a number of companies and businesses including Cyanamid; Monsanto; Preeceville Implements; UGG, Canora; Sask Wheat Pool; Sask Wheat Pool Farm Service Centre, Canora; Ducks Unlimited and Balawyder Seeds, Preeceville.