There are many variables to consider when calculating the optimal seeding rate for your malt barley crop, but one factor is certain – seeding rates are getting higher.
“Seeding rates have trended upwards for us pretty dramatically,” says Kelly Boles, owner-manager of Center Field Solutions, a full-service agronomy company based in Three Hills, Alberta. “For malt barley, we actually target fairly aggressive rates. We find that most years we can’t seed heavy enough. We’re creeping up the bar a little bit every year.”
Boles and his team are experts at providing their clients with highly customized rates for all crops. Their recommendation always starts with seed quality analysis, which provides a guideline to calculate the specific seed rate.
“We always drill right down to the particular farm and seed lot,” Boles says. Soil type, seeder performance and seed mortality rate all factor into the calculation.
Prescribing optimum rates
Just how high have seeding rates climbed in recent years? “We’re seeding many lots at 140 to 160 pounds per acre,” Boles says. “Our barley is heavier now. If we look at our seeding rates a decade ago versus now, our data shows that we’ve selected for heavier seed every year.”
Boles attributes the increase to a few different factors – for example, genetic development and selection by the breeders for large, plump kernels. “Then, as we clean seed to use to plant, we select for larger kernels in the seed lots,” he says. “Environment can also affect the kernel size. In years when we have smaller kernels, we would likely adjust the rate seeded.”
According to Boles, a malt barley grower should always target in the range of 28 to 35 live plants per square foot, which equates to about 30 to 40 seeds per square foot. That’s the equivalent of 300 to 400 seeds per square metre. “Our benchmarks right now are 28 seeds per square foot in the drier regions and 35 in the areas where there is enough moisture to sustain 35 live plants per square foot,” he says.
Benefits of using higher rates
Some growers may feel that rate is too aggressive for malt barley. But Boles cautions that by seeding too low, growers will miss out on the benefits that can be achieved with an optimal rate. One key advantage is a very uniform stand. This allows growers to target their fungicide application at the right time and enables a quicker harvest. Boles also cites another benefit: “If you don't have a void for weeds to fill because you've filled it with barley, then your barley is usually cleaner and more competitive.”
A higher seeding rate can also help with protein management, an important factor for malt quality. “I find that the higher seeding rate does help manage protein levels – it doesn't get so much nitrogen concentrated in each plant… all that nitrogen is diluted nicely into more plants. And that typically lowers protein,” Boles explains.
He adds that his rate suggestions also give growers peace of mind. “We find that we have a hard time seeding too much barley. There are mortalities and other things going on in the field, so having that higher rate is just an insurance. It’s a little safer bet to have a little higher rate than lower rates and the quality is always there.”
When rates are too high or low
Boles reminds growers, however, that you can seed too high. “The only negative effect would be if you do seed too heavy, then you can get some lodging, because we just can't control the height of that crop very well,” he says.
His watch-out for growers who use seeding rates that are too low is that the crop will have difficulty competing against wild oats. A crop seeded at a low rate also tends to be at various stages of development, which skews harvest timing.
“It seems there’s nothing detrimental when using high rates as compared to a field with a lower rate in the same area. When we do the plant counts, those crops with higher counts are usually just as good or better from a kernel plumpness standpoint, uniformity and quality, which lends itself more to malt.”