Forages - but I don't have Cattle

By Tim Nerbas, PAg

Conservation Agrologist

Are you considering seeding forages this spring? Of the approximately 49.6 million cultivated acres in Saskatchewan, 2.8 million acres are presently in tame hay production. There are also 6 million acres of rangeland and 1.1 million acres of improved pasture. These forage resources support a cattle herd in excess of 2.8 million head (cows, calves, yearlings and feeders).

The present drought has made it painfully evident that in order to maintain and eventually increase the livestock sector, more forage is required. Not only are forages an integral part of increasing the livestock numbers within the province, but they also may provide a viable alternative to chemical weed control options.

Over the last 50 years, producers have begun to rely more consistently on the use of pesticides to control weed, insect and disease outbreaks in our cropping systems. These products usually do an excellent job of control, but they have lead to a significant cost in growing a crop and subsequently a reduction in net returns to producers. As farmers, we have become more and more reliant on pesticides. Many of the good husbandry or best management practices (BMP) that could be incorporated into crop rotations have been lost in the shuffle.

One of the strengths of organic farming is its reliance on a variety of best management practices. Organic farmers can't rely on quick fixes in the form of pesticides. However, a new system called Pesticide Free Productionä from the University of Manitoba is looking to add another alternative. Unlike organic production, PFP does not need to be a long-term commitment. If the grower has a weed, insect, or disease outbreak during the growing season and a pesticide application is warranted, the producer can choose to do so. You simply lose the PFP production status for that year on that field. The field could then be placed back into PFP the next year.

Pesticide Free Productionä allows the use of fertilizers and pesticide applications outside the PFP crop's growing season. Crops cannot be treated with pesticides from the time of crop emergence until the time of marketing. But a producer can still use a preseed burnoff with Roundup as well as any post harvest applications required. However, special consideration must be made where residual pesticides are still considered commercially active in the soil. Pesticides are allowed during non-PFP crop years. Genetically modified crops or GMO's cannot be grown as a PFP crop.

Without relying on quick fixes to the same level, the producer must focus on long-term planning. For PFP to be successful the use of diverse cropping and other BMP's must be implemented.

As direct seeders we know the importance of both establishing a healthy crop and having a diverse rotation, one which includes pulses, oilseeds, cereals and if possible, winter cereals. But forages have always been a crop rotation afterthought. If you have livestock, you seed your worst field down to forages for extra grazing or hay. Otherwise every other arable acre must be in annual grain production. It seems to be an unspoken adage: "I know forages are good for the land but I need a cash crop now".

The benefit of nitrogen fixing plants in agriculture has long been recognized. Virgil (70-19 B.C.) made reference to the nitrogen fixing capability of alder:

"What was designated of old as the dense 'fat shadows' beneath which the green grass and the tender herb continued to flourish."

The inclusion of alfalfa or alfalfa/grass mixtures in crop rotations has many benefits, including increased soil organic matter. This perk will take on even greater importance if Canada ratifies Kyoto. Alfalfa also improves soil physical properties, reduces soil erosion, suppresses weeds and provides a disruption to plant disease cycles. Forage legumes have a unique ability to fix their own nitrogen, significantly reducing our reliance on non-renewable energy to produce nitrogen fertilizer. Not only do grain crops yield more after forages, but also the rotational benefit of field peas is greater where alfalfa has been included previously in the crop rotation (Table 1).

Table 1: Wheat yields as influenced by previous crop type (University of Manitoba). Note: no nitrogen fertilizer added to any of these rotations over the six-year study period. W-Wheat; P-Field Pea; B-Barley; A-Alfalfa.

A survey of 253 producers in 1992 in Manitoba and Saskatchewan indicated that producers recognized the yield benefits from forages, but few producers were managing forage stands for maximum rotational benefit. Producers tended to maximize forage stand length, only re-establishing when the existing stand had lost productivity. However research has shown that it takes only two to three years to obtain optimum N accumulation and weed suppression benefits from an alfalfa stand, while the optimum economic duration in Manitoba was determined to be four to five years.

Two factors thought to discourage producers from cycling forages through their rotation more frequently are: 1) problems establishing and 2) problems terminating perennial forage stands. However using direct seeding techniques is a proven way to increase the success of forage establishment, and using herbicides improves the ability to terminate forage stands. For instance, terminating forage stands using tillage is expensive (>$25/ac), time intensive, uses large amounts of fossil fuel, dries the soil and reduces many of the soil improvement benefits of the forage. Using herbicides typically costs less than $20/acre.

One of the unique abilities of forages is to suppress weeds. The competitive nature of forages for light and nutrients, and its frequent cutting reduces the vigour of weeds and their ability to produce seed. Work by Martin Entz at the U of Manitoba showed that wheat grown after alfalfa had reduced wild oat numbers to the same level as using a wild oat herbicide.

That's money in your pocket! So as you plan for 2003, forages maybe the factor you're missing. Oh, did I forget to mention forages are also good for cattle? Best of luck in the New Year!