WSU NWREC Forage Trials: Some Preliminary Results

Volume 5 Issue 9

Susan Kerr, WSU NW Regional Livestock and Dairy Extension Specialist

Several forage trials are underway at the Northwestern Research and Extension Center (NWREC) in Mount Vernon, WA. This article will share preliminary results of these demonstrations and variety trials. Tours of the plots can be conducted for interested persons; contact Susan Kerr at 360-848-6151 or kerrs@wsu.edu for arrangements.

Birdsfoot Trefoil

Birdsfoot trefoil (BFT) is a non-bloating legume, meaning it is a high protein forage that can be grazed fresh without the risk of bloat associated with alfalfa and some other legumes. It also has condensed tannins that are purported to help control internal parasites in livestock. Producers could consider it for grazing livestock; organic dairy producers could use it to help meet their 120 grazing day requirement without sacrificing the nutritional content of alfalfa and without the risk of bloat. It may be suitable for hay or haylage, too. It has the potential to become an invasive weedy species in some areas.

Demonstration plantings (100% BFT and 50% BFT-50% Timothy) in September 2014 were underwater in January 2015 (Photo 1, with annual ryegrass weed incursion), but ready for a first cutting in April. This apparent tolerance to waterlogged soil is a definite advantage for western WA production. BFT was seeded at 20# per acre and ¼” deep. Pre-planting fertilizer and BFT-specific inoculum were included. Five cuttings were made that year with production averaging 4.5 tons/acre. Results of the fresh forage chemical analysis on the 8/19/15 cutting are included in Table 1.

Photo 1. Fall-planted BFT underwater on Jan. 7, 2015 in Mount Vernon.

A BFT variety trial was planted on 9/17/15. Weeds were to be controlled with tillage and mowing, but the plot experienced severe weed pressure and chemical herbicide was applied in mid-June. The three varieties included:

1. Norcen from Stock Seed Farms, Murdock, Nebraska
2. Pardee from Allied Seed, Nampa ID
3. Witt from Allied Seed, Nampa ID

The Witt variety out-performed the other two throughout all growth stages at the NWREC variety plot.

BFT is reputed to be “difficult to establish,” but experiences at the NWREC BFT fall-planted plots tend toward concluding it is just slow to emerge, especially in cold, wet soils. Patience is rewarded, however, with vigorous and hardy plants what regrow well after harvest (Photo 2). Indeed, there are reports of >40-year-old BFT plants in Whatcom County that originated in conservation plantings. To see what difference in stand establishment and vigor might be seen with a spring planting, a small plot was seeded at the NWREC on June 7, 2016. The plants emerged much more quickly than in the fall plantings and have done well.

BFT’s best use may be as part of a grazing program. BFT hay made at the NWREC in August was unpalatable to horses and goats and ignored by steers on pasture. Due to unavoidable delays in harvesting, this hay was made from overmature BFT so its innate tannin content may have been too high for good palatability. Thanks to the recent acquisition of some haying equipment by the NWREC, hay can be made at more appropriate maturity levels in the future (weather depending) and palatability re-assessed.

Summer 2016 Forages

Teff, Italian ryegrass, and a sorghum-sudangrass hybrid were seeded in the first two weeks of June 2016. Teff and sudangrass are warm season C4 plants, meaning they thrive in hot summer months. Having alternative forages come on when C3 cool-season grasses are going into their summer slump would extend grazing options and even provide some forage for haying. Also, these annual grasses would provide another option for crop rotation systems. Teff is gaining popularity as horse hay due to its low nonstructural carbohydrate (sugar) content, which is highly desired by some horse owners, so this crop could become its own profit center for farms capable of making small bales. Teff is also being used as an income-producing crop as ground is transitioning from one crop use to another.

Teff established and grew well in the demonstration plot but was hampered by extreme weed pressure. It was planted elsewhere at the NWREC as a cover crop and soil stabilizer and has done well. The plot was mowed in mid-August and has responded well with regrowth; we hope for a second cutting. Hay from the first cutting was too weedy to feed; chemical analysis is pending.

A sorghum-sudangrass hybrid grew very poorly in the demonstration site, but very well elsewhere at the NWREC as a cover crop. Sudangrass must be fed carefully due to the possibility of prussic acid (cyanide) poisoning. The precursor compound is present in higher levels in young plants and plants affected by drought, wilting, freezing, trampling, and/or high fertilization rates. If grazing or feeding sudangrass greenchop, plants should be over 18” tall to reduce the risk of poisoning. Risk is greatly lower in sudangrass hay and silage. Sudangrasses are also often plowed under as a green manure.

The Italian ryegrass plot was very successful (Photo 3). It established quickly and shaded out weeds, so it had much less weed pressure than the other forage plots. It grew back very well after mowing. The plant was extremely palatable to cattle as both fresh forage and hay. This biennial cool season grass will not go to seed unless it goes through a winter, meaning it stays vegetative the entire first year of planting, producing an impressive quantity of high-quality forage. It can be planted in the spring for multiple harvests that year (winterkill likely) or planted in late summer for fall and spring grazing or harvest (winterkill less likely). Italian ryegrass dries poorly so is difficult to make into hay. It is best suited to grazing, greenchop, haylage, or baleage. It can fit into a farm’s forage plans as a rotational crop (not after corn, though) or emergency feed. It has the potential to become an invasive weedy species in some areas.

Photo 3. Five-week-old Italian ryegrass stand. Teff is on the left.

Photo 4. Blue River Hybrids corn silage variety trial at NWREC in Mount Vernon, 8/22/16.

Additional Forage Work

• We currently have a corn silage variety trial sponsored by Blue River Hybrids (Photo 4). Samples will be collected and data analyzed at the end of September; results will be made available to producers through various venues and on request.

• We are in Year Two of a simulated grazing impact trial on timothy. A stand planted in 2014 has been divided into three areas and “grazed” (mowed) at 3”, 6”, or 12” repeatedly. The middle height is thriving, but both the over- and under-grazed stands are struggling to various degrees. The purpose of this demonstration is to show the effects of repeated abuse and/or neglect on pasture grasses and motivate managers to follow best pasture management and grazing practices. These practices include never grazing or mowing below 6” and keeping plants vegetative and growing vigorously.

• Pumpkin feeding trial and ensiling experiment results were reported in the February 2016 issue of Whatcom Ag Monthly.

Future Forage Work

Additional forages to be studied in the future at the NWREC include sainfoin and festolium. Sainfoin is another non-bloating legume with high condensed tannin content; it is also naturally somewhat resistant to the herbicide glyphosate. It is better suited to dryland production and may not do well in western Washington’s wet clay soils. Plots will also be established in Centerville and San Juan County; it will be interesting to compare performance among these various soil types and precipitation zones. Festolium (a fescue-ryegrass hybrid) is purported to have more of the best traits and fewer of the undesirable traits of both ryegrass and fescue, meaning higher palatability, good persistence, good regrowth, better disease resistance, and higher winter hardiness.

We need to control weeds more aggressively in the variety trial and demonstration plots because weed growth is confounding some of the results. We also need to continue to build our haying capacity at the NWREC so we can harvest when needed and be independent of haying contractors’ schedules. Donations of haying equipment that fit into our long-term Research and Extension plans would be greatly appreciated.

Related Reading

• Condensed tannins: C.L. Marley, R. Cook, R. Keatinge, J. Barrett, and N.H. Lampkin. 2003. The effect of birdsfoot trefoil (Lotus corniculatus) and chicory (Cichorium intybus) on parasite intensities and performance of lambs naturally infected with helminth parasites. Veterinary Parasitology, 112:147–155. doi: 10.1016/S0304-4017(02)00412-0
• Birdsfoot trefoil
• Italian ryegrass (PDF)
• Festolium
• Sainfoin (PDF)
• Timothy
• Teff
• Sudangrass