Scientists at Agriculture Canada’s Semiarid Prairie Agricultural Research Centre (SPARC) in Swift Current, Sask. may have some good news for producers grappling with salinity problems on their farms.
As much as 20 per cent of cropland in Western Canada is affected by some degree of salinity and around four million acres have moderate to severe saline soils. A new Canadian cultivar, AC Saltlander Green Wheatgrass (ACS), is proving it can turn those acres back into productive land, while providing excellent pasture and hay for livestock.
Prior to the development of ACS the most salt-tolerant forage grass commonly available has been tall wheatgrass, but it has disadvantages that make its value as a forage crop low.
“Tall wheatgrass was not usually harvested at a time of the growing season when its nutritive characteristics were at its best,” says Dr. Harold Steppuhn, the leading developer of ACS. “It was usually harvested late, which meant that the fibre content was too large relative to some of the other constituents.”
What Steppuhn and his colleagues wanted was an alternative forage as salt tolerant as tall wheatgrass, but provide a better nutritional profile for livestock producers.
Working initially in collaboration with the Agricultural Research Service Laboratory in Utah, Steppuhn began work with seed collected in Turkey from a natural hybrid of a Eurasian blue-bunch wheatgrass complex and quackgrass.
LOOKS LIKE QUACKGRASS
ACS does bear some resemblance to quackgrass. “This new cross that has occurred naturally doesn’t necessarily have the same characteristics as quackgrass,” says Steppuhn. “It may look morphologically similar, but it is different; however it does have some of the beneficial characteristics of quackgrass, as far as being able to survive under saline conditions.”
Steppuhn’s initial research, which started about 14 years ago, concentrated on the salt tolerance of ACS, and was conducted at the Salt Tolerance Testing Laboratory at Swift Current, which is one of only three similar facilities worldwide. The other two are in Dubai and California.
Over the next decade a series of mass selection breeding cycles were conducted at Swift Current, where the resulting plants were evaluated not just for resistance to root-zone salinity, but also for winter hardiness, desirable plant morphology including uniform plant colour, vegetative vigour, leafiness, seed-set and freedom from plant pests.
WILL CATTLE EAT IT?
After having developed and registered the new Canadian AC Saltlander cultivar, the next step was to evaluate its performance in the field. So, in 2006, Dr. Alan Iwaasa, also with AAFC at Swift Current, began a project to assess the forage and grazing potential of ACS in comparison with other forage crops.
“We wanted to ascertain how would it do under grazing,” says Iwaasa. ‘Would animals eat it, what is the impact of the animals grazing, would grazing influence it as far as its longevity?”
Six pastures, each 1.2 ha, were randomly seeded to ACS or Smooth Bromegrass (SB) (Carlton) in the spring of 2006. Seeding rate for the ACS and SB were nine kgs and 6.7 kgs per ha respectively. Grazing on all six pastures occurred in June of 2008 and 2009, while the forages were at the boot to heading stage of growth.
Results over the past three years found that the forage dry matter production of ACS and SB at the time of grazing in June were similar, with ACS higher in all years. Growing conditions were quite variable from 2007 to 2009 with all years having limited spring moisture conditions.
Grazing performance, averaged over two years (2008 and 2009), was higher for ACS versus SB and average daily gains were 1.06 and 0.78 kg. per day, respectively. Grazing behaviour did not appear to be different between forage/pasture types. The forage quality values between ACS and the brome are similar. However, the SB had a higher percentage of crude protein and was lower in fibre, which would explain the higher percentage of organic matter digestibility observed.
Total grazing days provided by the two pastures was 115 days/ ha each. Total live productions forACSvs. SB were61and47kg/ ha, respectively. Better cattle performance observed in 2008 and 2009 for the ACS versus SB may be due to the better regrowth potential of ACS, since in 2008 and 2009 good summer moisture conditions were observed. The data obtained, however, is only preliminary and more years of data collection will be required to indicate how AC Saltlander ultimately performs.
“Because we have had two years of dry spring conditions and the grazing time we were able to apply to these two forages were a lot less than we wanted, I don’t want to suggest these are set values,” cautions Iwaasa. He adds the study will continue for at least another two years to evaluate results under various environmental conditions. “But we have seen that animals don’t any problems as far as grazing ACS at the same time as the SB. There doesn’t seem to be a palatability concern, and the average gains between the ACS and SB are similar, so that gives us a good idea that performance is probably very similar to what we’ve seen in the SB.”
A significant difference between the two types, however, is that SB is really destined to be a hay crop, whereas ACS may exhibit greater regrowth potential. “ACS seems to maintain its green appearance and that could offer another opportunity to graze or hay after the late spring/early summer period of time,” says Iwaasa He’s hoping growing conditions in 2010 will allow for a second grazing of the ACS to evaluate this potential.
Ken Miller, of Miller Seeds in Milk River, Alberta, holds the North American distribution rights to ACS. He has evaluated it for both agronomic and livestock performance on his own farm.
“There’s a picture on our website of cows up to their bellies in a field of ACS, in an area that was useless just a few years before that,” says Miller. “After harvesting the seed, we bale the aftermath behind the combines — the straw so to speak — and we winter cows very nicely on that. The plants are mature when harvested, but the protein and energy content is adequate for wintering cows. It’s not a tough-stemmed crop like tall wheatgrass and it’s soft in their mouths and they take it in very nicely. We also use it as part of the ration for back-grounding calves and they accept it very well.”
RECLAIM SALINE AREAS
The other important issue driving the development of AC Saltlander and research into other salt tolerant varieties of alfalfa, is the ongoing need to turn unproductive saline soils back into economically viable land. It’s an issue that could be front and centre in the future, according to Iwaasa.
“We are undergoing various climate-change situations, particularly in Western Canada, and we feel the drier conditions we may face, could result in definite concerns as far as an increase in salinity in the soil,” he says. “We already have a big push towards using irrigation to counterbalance lack of moisture in certain situations, and so this whole salinity issue is not going to go away, and it could dramatically increase.”
Miller has also seen the effectiveness of ACS in reclaiming saline land on his own farm.
“Five years ago we seeded a severely saline patch of land to a mixture that was mainly ACS and we have reclaimed that land and dried up the saline areas,” says Miller. “At one time the saline patches were about 20 per cent of the area and that has shrunk to two or three acres that are still too salinized to grow the ACS.”
Even those highly saline areas will eventually be recovered as the ACS continues to lower the salt accumulation in the area soil and ground water.
“The ACS is able to lower the water table and use that salty water before it gets to the surface,” says Miller. “It’s when salinized water gets to the surface and evaporates that it leaves its salts behind in white patches. So by lowering the water table the salts are able to go back into the soil and the surface areas are not so heavily salinized.”
Miller notes you can’t just seed a
little ring around the saline patch-es. If there is a five-acre salinized patch it is best to seed 20 to 30 acres around it, creating sufficient regional use of that salty water for the groundwater level to drop.
SUPPRESS FOXTAIL BARLEY
Another agronomic advantage for AC Saltlander — still being evaluated — is its effectiveness as a biological control to suppress foxtail barley (FB).
Foxtail barley, as most producers know, is a major weed proven hard to control, especially in hay fields with saline soils, where it establishes itself thanks to its salt-tolerant qualities.
Miller has also done on-farm trials in areas with foxtail barley and found AC Saltlander can definitely help control the persistent weed, when used in conjunction with other weed control measures.
“You can’t just scatter ACS in a field of foxtail barley and expect it to take over,” says Miller. “You need to destroy the existing FB and deal with the seed bank that is there.” Deep tillage is one option, which buries FB barley seeds deep where they can’t germinate.
The Swift Current scientists are in the fourth year of testing the effectiveness of 10 different forage species for suppressing FB across saline test sites in Alberta and Saskatchewan. A mix of ACS and slender wheatgrass has so far proven to be the most successful combination in displacing FB.
Probably the only disadvantage with AC Saltlander is the higher cost of seed, which should come down as supply increases. Iwaasa hopes further research will help counter the initial seed cost by proving the long-term sustainability of ACS, which requires very few inputs once established.
“We don’t want something producers will have to reseed after a couple of years, because it is a huge cost to break land,” he says. “On all of our production systems here at AAFC we are interested in developing sustainable systems, so we’re not looking to put in a lot of inputs such as inorganic fertilisers. We will see how these production values play out over the life of this project.”
For more information on AC Saltlander visit the Miller Seeds website at: http://millerseeds.com/acsaltlander.php
Angela Lovell is a freelance writer based in Manitoba