Agronomy Library > Soil Conservation

A Measured Approach to Direct Seeding - Don Boles, Three Hills, AB
Author: Sandra Taillieu
Date Created: January 10, 2005
Last Reviewed: January 10, 2005

Don Boles farms a mix of heavy clay and loam soils at Three Hills, Alberta. He direct-seeds peas, wheat, canola and barley on his own farm and also does custom work for some of his neighbours. He is an active director for the Alberta Pulse Growers and a dedicated member of the FarmTech organizing committee.
“We started direct seeding in 1992 for the purpose of controlling wind erosion and for moisture conservation,” says Don. “Tied in with the usual reasons of decreased fuel and maintenance costs, we got a new seeder that allowed us to double shoot.”
“Now I seed with a 5000 Flexicoil air drill with 6 inch sweeps on 12 inch spacing and 5.5 inch rubber packers,” says Don. “We use a splitter boot that puts the fertilizer down at the same depth as the seed. I also have auto-track on my tractor to eliminate over-lap and to help keep the fields more even.
“I straight cut everything except our canola. This year we added a MAV (Maximum Air Velocity) Redekopp chopper to our combine. It was supposed to cut the straw fine and spread both chaff and straw evenly. Both things it accomplished with a roaring success. I won’t need to harrow except to incorporate Edge prior to peas.”
Don considers research work from across the prairies. “I try to look at all the data and then see what makes sense for my farm,” says Don. He combines this knowledge with his own farming experience for a measured approach to direct seeding.

Seeding Rates
Don has practiced what researchers have consistently found: growing healthy, competitive crops starts with a doing a good job of seeding. “High seeding rates benefit the crop’s ability to compete with weeds and to mature evenly,” says Don.
“First I select quality seed, do tests for germination, vigour and fusarium,” explains Don. “I try to use seed with at least 90% germination. Research suggests that even with 100% germination, the number of seeds that result in viable plants can be as low as 80% for peas, 75% for wheat, 70% for barley and 50% for canola. “
“I sow in seeds/square meter,” says Don. “For example, I grow Superb wheat. Superb is a large seeded variety so if you are going to seed in lbs/ac or bu/ac, you are probably seeding too light.
“Last year my Superb wheat had a seed weight of 43 mg (43 g/1000 seeds). I wanted 400 seeds/square meter so I just multiplied 43 mg x 4 = 172 kg/ha for my seeding rate.
“The worst thing you can do is plant this seed too light. Superb is a late variety and it tillers like crazy. If you have a low plant populations, the maturity of the seeds will be un-even and take longer to fully mature.”
Don’s investment in seed in the spring makes a real difference at harvest. “Last year I tried two seeding rates with Kendall barley,” says Don. “My seed weight was 40 mg (40 g/1000 seeds). I seeded some on higher ground at 80 Kg/ha for a seed population of 200 seeds/m2. Two and a half weeks later I seeded the same barley on a piece of land close to a creek on frosty ground at 120 Kg/ha for a seed population of 300 seeds/m2. The crop stand at 300 seeds/m2 was clearly denser, more even with less tillering and it matured more quickly. There were also obviously fewer weeds with the higher plant populations.
“An average seeding rate for barley in this area likely falls between 200 seeds/m2 and 300 seeds/m2. With wheat, earlier maturity is even more important. Based on what I’ve seen, I’ll seed at least 300 seeds/m2 for barley and wheat. I’ll seed 400 seeds/m2 on frosty ground.”
Don also uses metric to calculate his seeding rate for peas. “Peas are so simple to figure. As with cereals, I select seed with germination above 90%. How ever many milligrams the seed weight (average weight of one seed), I take that number and seed the same amount in Kg/ha to give me 100 seeds/square meter.”
“Seeding canola is different because of the exorbitant seed costs,” says Don. “I generally only grow Invigor varieties and I only seed 4.5 Kg/ha to 5 Kg/ha. It is a good thing this variety is more vigorous because it’s a larger seed and more costly to seed.”

Seeding Rate:
Thousand Seed Weight (g)    10 000 m2      target seed population     1 Kilogram                                   Kilograms
------------------------------------ X   --------- X -- -------------------------- X ------------  = Seeding rate in   ------------
 1000 seeds                           1 hectare                   m2                         1 000 grams                                hectare
Don’s short-cut:
 Seed weight (mg)           target seed population/ m2                                    Kilograms
------------------------- X   ------------------------------------ = Seeding rate in ---------------
        1 seed                                      100                                                         hectare
Thousand Seed Weight= 43 grams            Seed Weight/1 seed = 43 mg               Target Seeding Rate = 400 seeds/m2
   400 seeds/ m2         
43 mg X   ---------------------- = Seeding rate of 172 Kilograms/hectare
To adjust for germination and mortality, simply divide the seeding rate in kilograms/hectare by the percent expected survival.
Example: 172 Kilograms/hectare of seed at 90% expected survival
                172 divided by 0.90 = 191 Kilograms/hectare
Calculation for Nitrogen (N) Removed with the Grain for Wheat:
% Protein                                                                                    
----------------- = % N in the grain             % Nitrogen X Yield (Kg/ha) = Weight of N removed with the grain in Kg/ha
Yield of wheat= 5400 Kg/ha                   % protein= 13.5%
------- = 2.37 % N in the grain                      2.37% X 5400 Kg/ha = 128 Kg/ha of N removed with the grain
Calculation for Nitrogen Removed with the Grain for Barley, Canola & Peas:
% Protein                                                                
----------------- = % N in the grain             % Nitrogen X Yield (Kg/ha) = Weight of N removed with the grain in Kg/ha

Seeding Dates

Don starts seeding early. “If the weather doesn’t crater on me, I can get the crop in the ground in ten days,” says Don. “I like to be done by the 10th of May. When I was in school 35 years ago, that’s when we would start!
“It’s got to the point where we want to seed everything first. I usually start with peas around April 20-25th. I want to get them in the ground for an early harvest. Then I seed my cereals and canola. It’s at the point where I want to seed everything first. But when you seed so early in the spring, order is less important than getting everything seeded early.”
Don admits there are years when there are issues of frost and cold spring weather but he insists: “As producers, we can only play with averages and I’ve had my best results seeding early.”

In-Crop Weed Control
Don applies a measured approach to herbicide application by only applying a rate to kill the weeds that are reducing his yield.
Don has taken the research results from the Agronomy program at Agriculture Canada in Lacombe and applied them on his farm to improve the economics of his weed control program. He has reduced his chemical bill by increasing his seeding rates and carefully managing the timing and rate of herbicide application.
“I like to spray at earlier crop and weed stages,” explains Don. “This comes straight out of the research showing that by spraying earlier, it is easier to kill the weeds that are taking more of my yield. And, as a rule of thumb, the crop metabolizes most herbicides better at earlier stages of growth. Generally, I finish spraying by the third week of June.”
“I don’t believe in spraying for cosmetics and I don’t believe in throwing money at the field just to make myself feel better,” he says.
“I religiously read every label even if it is a chemical I’ve used for years. It’s probably the most important thing you’ll read all year. Then I spray at the rate I need for the weeds that I have.” Don avoids over-application of herbicide.
“When I spray, I use metric too,” explains Don. “I apply chemical in L/ha and it’s just so much easier. I’ll give you a classic example. I think a lot of Liberty in this area is applied at 1.35 L/ac of Liberty. What a waste of money! I read the label and for my weed spectrum, I only need 1.35 L/ha of Liberty. I mix it with 63mL/ha of Select for my grassy weeds as Liberty is weak on grasses. Label reading helps me to do a better job of spraying and saves me money too.”
“It’s not that I’m cheap when it comes to spending money on chemical,” explains Don, “It’s because I’m trying to reduce the impact of herbicides on the environment – you understand?”
Don also is careful with his choice of chemicals to give him flexibility in his crop rotation. “I don’t like residual chemicals as a rule. If I decide to alter my crop rotation, I don’t have a problem.”

Don’s measured approach to direct seeding extends to his fertility program as well.
“I study the nutrients I remove in crop product taken off the field and try to replace them,” says Don. “We’re trying to build the soil, not rob it. The fact is I removed 100-150 Kg/ha of N from my soil bank and exported it with my wheat crop.
“Nitrogen is by far the most important nutrient. If my wheat or barley is at 13.5% protein or higher, I likely maximized my yield. This helps me to decide if I’ve applied enough nitrogen or not.”
“I don’t cut back on nitrogen fertilization after peas,” says Don. “I try to capitalize on the improved soil condition and rotational benefits. With my soil and climatic conditions, that means I fertilize.”
“The only problem is that the cost of fertilizer is increasing while the value of the crop is decreasing. But, if I rob my soil fertility, it’s going to cost me in long-term productivity.” And for Don, sustainable productivity is a measure of success.
Check out this link:
Seeding rate calculator: