Annual Forages Proving Worth in Saskatchewan

REGINA - May 18/04 - GPR -- The second year of a research project that took place at six sites in the province is poised to answer the much-debated question about the adaptive quality and potential for warm-season crops as annual forages in Saskatchewan, says Lorne Klein, a rangeland and forage agrologist with Saskatchewan Agriculture, Food and Rural Revitalization in Weyburn. Second-year results are now available.

"Perennials are the corner post of the livestock production system, but annuals can provide supplemental and emergency forage production, especially with the availability of new species and varieties of warm- season grasses. The latter have particular use in a swath-grazing system," says Klein.

Scott, Redvers, Canora, Melfort, Swift Current and Indian Head are the sites, and the cool-season crops being studied are AC Pinnacle oats and AC Ranger barley. The warm-season crops are Crown millet, Golden German millet, Forage King sorghum-sudangrass and Pioneer 39T71 corn. Additional crops were seeded at Redvers, Canora and Indian Head: Siberian Red millet, Strain R German millet, White Wonder foxtail millet and Mil Hy 300 Pearl millet. The project involves two seeding dates - mid-May and mid-June - and two harvest times: at the normal time for green feed, and a second harvest two weeks later.

"Our 2003 results showed that, as expected, the dry matter yield of the cool-season annual cereals - oats and barley - tended to decrease with the later seeding date," says Klein. "The seeding date did not have a consistent effect on the yield of the warm-season annuals, however. Corn had the highest yield, while the yields of barley, oats, and Crown and Golden German millet were not statistically different from each other."

When averaged over all crops and locations, and both seeding dates, the second harvest had significantly higher yield than the first harvest. Crude protein tended to increase when seeding was delayed, and decrease when the crop was harvested at a later stage. Weathering in the windrow until December had very little effect on the crude protein.

Total digestible nutrients (TDN) were not affected by seeding date or harvest time. When samples were left to weather in the windrow and were averaged across all locations, however, the earlier maturing crops - oats, barley and Crown millet - showed statistically significant declines in TDN from second harvest to the December sample.

"At the eastern Saskatchewan sites, the late maturing millets, such as Golden German, Strain R German and White Wonder, appear suited for swath grazing," says Klein. "But the seeding of warm-season crops needs to be delayed until early June, when the soil has warmed to a minimum daily soil temperature of 10°C. Because of later maturity and tolerance to warmer temperatures, these crops remain green and continue to grow late in the season. They can be cut in early- to mid-September, just prior to a killing frost, with little risk of weathering in the windrow due to short day length and cool temperatures."

Oats and barley are not ideally suited for swath grazing, he says. To maximize yield under normal conditions, oats and barley need to be seeded May 20-25 to take advantage of spring moisture and cooler temperatures. When they are seeded this early for swath grazing, however, they need to be cut in early August, which means they are subjected to long daylight, warm temperatures and the potential for significant weathering.

"Seeding of cool-season crops can be delayed to mid-June to delay cutting, but there is a high probability that yield will be reduced. As a general rule, for each week that seeding is delayed past May 25, a 10 per cent loss in yield should be expected," says Klein.

Seed cost has also been considered in the project. While corn was the highest yielding crop in the trial, the relatively high price of corn seed requires significantly higher yield to justify the cost of production, Klein says. The seed costs of the millets and sorghum-sudangrass have been similar to oats and barley in the past, but now they are somewhat higher than the cost of these cool season crops. He says future work with corn will need to factor in the price of seed to determine if corn is an economical forage alternative.

An interesting observation was also discussed in the 2003 report. It points out that the native tall-grass prairie region of Western Canada stretches through central Manitoba, including the Red River Valley and wide bands on either side. Before European settlement, the tall grass prairie was dominated by Big Bluestem, a warm-season grass.

"Of the trial sites, Redvers, Indian Head and Canora are geographically the closest to the Red River Valley. These sites showed Golden German millet had a significant yield advantage over oats and barley. It may be that these sites have a climate that favors warm-season crops more than sites in western Saskatchewan," concludes Klein.

The project trials will continue at Scott, Canora and Indian Head this year. A final report, which will include similar trials at Redvers, Canora and Indian Head in 2002, will summarize three years of data.