High yields and good milling quality are what most oat producers strive for, and achieving these goals may depend on where they are grown and under what kind of production system.
Soil and environmental conditions definitely have an impact on seeding rates and timing, which are all important factors in the quest for a perfect oat crop. Here are eight things farmers can do to achieve high yields and good milling quality.
MANAGE WILD OATS
Managing wild oats is probably the biggest concern for many farmers in light of the lack or registered herbicide options for in-crop control. The first step in managing wild oats, say most experts, is careful field selection. “Farmers should try to avoid fields where they have known high wild oat populations,” says Pam deRocquigny, cereal crop specialist with Manitoba Agriculture, Food &Rural Initiatives (MAFRI).
Planning rotations and planting crops that have good in-crop control options in fields where you plan to grow oats a couple of years down the road is also a good idea to try and reduce the wild oat seed bank in the soil.
“If farmers can grow crops ahead of time where they can use a grassy herbicide that should help clean out the wild oats,” says Jennifer Mitchell-Fetch, an oat breeder at Agriculture and Agri-Food Canada’s Cereal Research Centre at Winnipeg.
No-till systems also have an advantage when it comes to controlling wild oats, according to William May, a crop management agronomist at AAFC’s Semiarid Prairie Agricultural Research Centre at Indian Head, Sask. “You can seed earlier in a no-till situation and still manage your wild oats very well,” he says. “Delaying seeding to control wild oats can have a negative impact on yields.” Which brings us to the next point.
A pre-seed burnoff of the first flush of wild oats is an option if it’s not too wet to get into the fields early on, says deRocquigny, but waiting too long for the weeds to emerge may jeopardize the crop overall. “If you can get the crop up and going before the wild oats even emerge you are going to see less impact on yield than if you are seeding into a field where the wild oats are emerging ahead of the crop,” she says.
Seeding early is also an advantage for farmers wanting to achieve milling quality. “Research shows oats seeded later are much lighter, so you want to get the crop in early,” says deRocqigny. “Both yield and quality can drop significantly in oats seeded after May 15th.”
BUMP SEEDING RATES
Oats should be sown at a higher seeding rate to reduce the impact of wild oats. This may increased the risk of lodging so variety selection is also important.
“Choosing an oat variety that has good lodging resistance might be a good option,” says deRocquigny, who adds that it’s important not to simply think in bushels per acre when it comes to targeting seeding rates. “You need to take into consideration your 1,000 kernel weights, your plant population per square foot and your expected seedling survival to help you figure out a seeding rate that will achieve the target plant stand that you want,” she says. “There can be quite a bit of difference in 1,000 kernel weights because of seed size.”
Hulless oats have a thin seed coat that is subject to cracking and which can lead to lower germination, so it’s important to know the level of germination in order to adjust the seeding rate, which MAFRI recommends as 48 to 62 lb./ac. or whatever is required to achieve a plant population of 194 to 250 plants per m (18 to 23 plants/ft2 ).
May and his team has done a lot of research into seeding rates for oats and he recommends an optimum seeding rate of 375 plants per m to help control wild oats and achieve per cent uniform, high yielding stands. “Maintaining a high seeding rate and a uniform stand really reduced the amount of wild oat seed in harvested samples and in the biomass,” says May.
May recommends seeding at a minimum of 300 plants per m, and never going below 250 plants per m. “At 300 plants per m I have a more even stand and earlier, more even maturity,” he adds.
MAFRI provides detailed information on its website about calculating optimum seeding rates using plant populations, but plant density recommendations can vary in different areas.
GROW FOR THE MARKET
Doing everything right to achieve full yield potential and milling quality won’t make much difference if you are growing a variety that the miller doesn’t like. As obvious as this may sound, deRoquigny advises farmers to check with the miller who will be purchasing their oats that the variety they are thinking of growing is on their preferred list and will be acceptable to them.
SELECT THE RIGHT VARIETY
As with many other crops, there are trade-offs with different oat varieties. For example, Pinnacle is a long season variety that gives higher yields, but it doesn’t have resistance to crown rust, which is one of the most problematic diseases of oats, particularly in Manitoba.
Crown rust can cause 100 per cent yield loss in susceptible varieties. It can also drastically reduce oat quality by causing thin kernels with low test weights.
Choosing a variety resistant to crown rust should be the first step in trying to mitigate its impact, especially in rust-prone areas. Many of the most recently released cultivars are rated as having either moderate resistance or resistance to crown rust. “There are susceptible varieties grown here in Manitoba, but farmers should probably make sure to allow for a fungicide application in their cost of production,” says deRocquigny.
APPLY OPTIMAL LEVELS OF N
Fertilization of oats is relatively uncomplicated compared to most other crops. Nitrogen is probably the most crucial element. Too much N and there will be a reduction in test weights and plump kernels, which are the main things millers look for in oat crops. Too little N and there will be reduced tillering, which negatively affects yield.
But when it comes to oats, where you grow them is a significant factor in the amount of N you are going to need. “There is a very clear division in fertility with oats,” says May. “There’s the Red River Valley region of Manitoba and then there’s the rest of Western Canada.”
His research has shown that in areas outside of the Red River Valley, there is no yield advantage in putting down more than 55 lb./ ac. of N. “Once we are above 55 pounds an acre the probability of getting a yield increase is low, and you could have the potential to push test weights down,” says May. “For a farmer in Western Manitoba and Saskatchewan or Alberta, 30 to 55 lb./ac. of N is sufficient.”
MAFRI recommends starting with a soil test. “A soil test is vital,” says deRocquigny, “so farmers can accurately calculate how much N they need to apply.”
“In Manitoba the nitrogen recommendation for oats is: N fertilizer required (lb./ac.) = 100 lb. of N/acre minus soil nitrate (lb./ac.) in the first two feet,” she says. “Research has shown there is no adjustment of this rate required by expected field potential, so it doesn’t matter what your yield potential is the guideline remains the same.”
HARVEST SLOWLY AND AT THE RIGHT TIME
Careful timing of harvest and taking care not to damage or de-hull the oat kernels are also considerations that will affect both crop yield and quality. It can be difficult to judge when the crop is ready because there is often variability within the field. Highest yields are obtained by swathing when the kernel moisture content is about 35 per cent and when the greenest kernels have just changed to a creamy colour.
To obtain highest milling grades, no green hulls or dehulled kernels should be present. Slower cylinder speeds of around 900 r.p.m. and wider concave clearances will help to prevent damage and are especially important when harvesting hulless oats, which are much more vulnerable.
Combining a standing crop of oats with a straight cut header is an option when the land is uniform, a high seeding rate was used, the crop was seeded early and is maturing in August, says May.
USE WIDER ROWS IN NO-TILL
New research is currently under way, using oats as a sample crop, to maximize the benefits of seeding into a no-till system. Previous studies have demonstrated that, especially in the drier areas of the Prairies, there are microclimatic benefits to seeding crops into tall rather than short stubble. A study at Swift Current found that by keeping the stubble at 12 to 14 inches they were able to improve the water use efficiency of the plants and increase yields by 14 to 17 per cent depending on the crop. Now a team at AAFC’s Indian Head Research Farm in Saskatchewan, in association with the Indian Head Agricultural Research Foundation, the Saskatchewan Oat Development Commission and SeedMaster at Regina is taking the research one step further to evaluate the effect of wide row spacing on oat yield and quality.
“What we are saying is we need to be able to seed between the rows in order to maintain the standing stubble,” says Guy Lafond, a production systems agronomy scientist at Indian Head. “In order to do that more effectively we are looking at the potential for wider row spacings.”
As one component of the elaborate study that Lafond and his colleagues set up, they are evaluating 10, 12, 14 and 16 inch row spacing and over the past two years have been able to maintain yields up to a 14 inch spacing with no impact on how the plant tillers develop and the number of tillers produced.
The effect of fertilization at wider row spacing is also being studied. Using the same row spacings, researchers varied rates of nitrogen, whilst maintaining the same rate of phosphorus, potassium and sulphur. They used a commercial SeedMaster side band fertilizer opener, so that as they increased the width of the distance between the rows, the fertilizer became more concentrated beside the seed row. per cent “Most people want to side-band or mid-row band their fertilizer requirements at time of seeding,” says Lafond. “So we are saying if we go to wider row spacing, we need to be careful that the fertilizer doesn’t become too concentrated beside the row when using a side-banded configuration.”
So far they have not found any fertilizer damage when measuring the plant stands. “The concentration of fertilizer isn’t bothering the oats that much as we increase the row spacing but it looks likely that 14 inches might be the maximum row spacing we can go with oats,” says May, who is also involved in the research. One more year of research is being planned.
In 2011, field scale studies will be initiated with canola to study the problems and issues associated with seeding between the rows on 12 inch spacing into tall stubble harvested with a stripper header. Lafond says, “We are very excited, because to implement a technology like this is not very expensive for farmers and the benefits in a dry year could be enormous.”
As an update to the above article, Grainews regrets that Guy Lafond passed away in April 2013.