Greenseeker Hits the FarmPosted in: Farming By Bill Strautman June 1 2009
While Greenseeker technology has been tested for a number of years in western Canada, it hasn’t been used commercially. But in the spring of 2009, at least two Saskatchewan farms plan to take the plunge and try using the system on their operations.
Greenseeker sensors measure crop nitrogen deficiencies in real time, then predict yield potential for the crop using the agronomic vegetative index NDVI. A nitrogen recommendation, based on inseason yield potential and the responsiveness of the crop to additional nitrogen, allows variable rate top dressing to occur on the go.
A Greenseeker sensor, mounted on a sprayer boom, can calculate a vegetative index and recommend how much additional nitrogen needs to be top dressed to optimize yield potential
Rick Pattison with Pattison Liquid Systems in Lemberg, Sask. says five or six years ago, NTech Industries, the people that make Greenseeker, contacted him to see if he’d be interested in
working with them.
“I told them I was quite interested, but that we wouldn’t sell any until we could proof the algorithms under our conditions. What happens in Oklahoma doesn’t happen in Saskatchewan,” says Pattison.
A few handheld units have been sold, but they’ve all gone into research situations. Steve Shirtliffe, an associate professor in the Plant Science department at the University of Saskatchewan, plans to use one this year to estimate biomass production on a flax fibre project this summer, with Brandon Ag Canada researcher Byron Irvine.
But Pattison didn’t pursue selling any commercially until the spring of 2009.
“There’s no point going out until we knew it was working. We’re now at the point where we can go forward with it. We got Guy Lafond and Chris Holzapfel, Ag Canada researchers from Indian Head involved and they’re redoing the algorithms to work with our climate,” he says.
Lafond says before Greenseeker could go to market, they had to develop the algorithms for western Canadian crops under western Canadian conditions.
“We have the algorithms finished for spring wheat and canola, so if you bought a Greenseeker today, these equations are built into it, running in the background. We’re working on oat, durum, malting barley and winter wheat. We have the first generation of equations for these crops,” says Lafond.
The whole idea of the technology is to refine your ability to arrive at a more optimum rate of nitrogen.
“When you use the Greenseeker, you always have an ‘N rich strip’ where you have 1.5 times the regular rate on the field. Then you can do a comparison between the N rich strip and the restof the field, and adjust your nitrogen application accordingly,” says Lafond.
“The process we use is applying only 66 percent of the recommended N rate. That way, you don’t over fertilize the areas that don’t need it. Then you come back in with the Greenseeker and top it up if the crop needs it.”
Lafond suggests that this is one way to use the system, but another option would be for farmers to go with their regular rate of fertilizer, then check to see if they were close compared to the N rich strip. At that point, they can make a decision to add more.
Timing for making the Greenseeker pass is similar to the timing for making a split nitrogen fertilizer application.
“With cereals, there has to be at least five leaves, to the emergence of the flag leaf. That’s the window that we want people to use. With canola, the window is the start of bolting to the start of the appearance of a few flowers. If you go later, you won’t necessarily capture yield,” says Lafond.
The system is based on a liquid nitrogen top dress, because it has to be tied into a liquid applicator. The Greenseeker sensors are mounted on a sprayer boom and modifications made to the sprayer for applying liquid fertilizer.
Managing nitrogen fertilizer will be the initial application for the technology, but Lafond says that because the sensor measurements can be related to a final grain yield prediction, other applications may arise.
If a farmer needs a minimum yield of 40 bushels per acre to make fungicide application worthwhile, the Greenseeker can estimate yield potential, then only apply that fungicide where the yield potential meets that standard.
Another application might be for mapping their fields.
“A field will not behave the same from one year to the next, because it’s a function of weather, temperature, moisture and how much N is mineralized. Greenseeker takes that all into consideration, plus spatial variability across the field. And it’s simple to use,” says Lafond.
Farmers take the Greenseeker plunge
Lee Moats - Riceton, Sask.
Lee Moats farms on flat, heavy clay land at Riceton, just south of Regina. While topography isn’t an issue, drainage in wet years and the notoriously finicky soil provides plenty of challenges.
Moats says he’s interested in Greenseeker technology for two reasons.
“The first is risk. After coming off a dry spring in 2008, the risk of applying a large amount of nitrogen, which we’re very used to doing, was compounded by having such dry conditions that the nitrogen didn’t return us anything at all. Had we not put on the high nitrogen levels we did last year, we’d have saved a significant amount of money,” says Moats.
“You’re applying a high value input on the basis of your expectation for the year. The idea with Greenseeker is it puts at least a portion of that high valued input on at a time you’re more certain to get a return on it.”
“In the event that you have a spring like 2008, you just wouldn’t put it on because there would be no expectation for return. That’s the nearby motivational force. There’s nothing like having a disaster to motivate you to look at alternatives.”
The second aspect for Moats is figuring out how variable rate application would work. He says there’s been a lot of work trying remote sensing, intensive soil testing and so forth, to write prescriptions.
“The dilemma we face on our farm is that many of those techniques don’t give you relevant information to write a prescription with. We know if we grow a good crop, the soil tests are all going to show a similar level of deficiency and not enough variance to write a prescription. And remote sensing is frequently sensing something that is not the nitrogen component,” he says.
“If you did remote sensing on our farm last year, you’d find areas where we didn’t have germination because it was too wet. Again, that’s not related to nitrogen.”
Moats says farmers are used to applying nitrogen based on yield potential. When nitrogen is cheap you can afford to do that.
“We imagine we’re going to grow a 40-bushel canola crop and fertilizer accordingly. But when you look at long term crop insurance yields, it’s at 30.5. So we’re automatically conditioned to fertilize for more than we produce a lot of the time,” he says.
“Our challenge is to see how little fertilizer can we put on relative to risk and still be assured of using it all. We’re not very sophisticated in relating yield probability to nitrogen rate, which is one of our future challenges.”
The idea with Greenseeker is that you’re measuring a real time crop condition, which then gives you the ability to respond with nitrogen that’s truly related to a nitrogen deficiency, where you have an expectation that you’ll get a return from the nitrogen.
And you’re doing it at a time when your degree of risk is a lot less. You’ve got a live crop there, these sensors tell you how it’s doing, so you should have a higher incidence of return for your investment.
“It’s providing a variable rate prescription that’s actually meaningful relative to your crop on that particular year. That side is all very exciting to me. The other spinoff is that the NDVI readings you get out of the Greenseeker is the same technology that the remote sensing is using to rate crop conditions,” says Moats.
“You get all that information that you can use to look at management zones. If you get real sophisticated, you can then relate that to yield maps from your combine and do economic analysis based on that.”
Moats plans to mount his Greenseeker sensors on the booms of a pull-type suspended boom sprayer.
“The challenge is, if you’re in a situation where there’s lots of variability, you need to be able to put on highly variable rates. You might need two gallons here and twelve gallons over there. Fortunately, there’s a sprayer nozzle available that puts out a wide range of rates, based on varying pressures,” he says.
“You have to add the nozzles, get a variable rate controller and GPS that will talk to the Greenseeker - you have to get all those components in place to make it work.”
For the first year, Moats plans to apply a base rate, about four sevenths of normal.
“We’re going to put on 40 pounds, where we normally put on 70 pounds of N, so that’s around 60 percent. If growing conditions aren’t good, we haven’t wasted much nitrogen. We have enoughnitrogen to get us to the point where a split application is viable,” he says.
“If you didn’t put on any nitrogen, you’re setting yourself up for a nitrogen deficient crop that can’t recover the yield potential that it would have had if there was adequate nitrogen. We’ve been down that winter wheat road often enough that you don’t want to go there. Once you’ve got a nitrogen deficient crop, you’re never going to get the yield potential back. So it’s a split application scenario.”
Moats says there are a lot of things that are all related, but the biggest one is not putting a bunch of nitrogen on when you don’t need it. Hopefully, that also means putting on nitrogen where you do need it.
“I think it has a lot of potential. The higher nitrogen prices go, the more interested we’ll be in having something that does this,” he says.
“And the more interest there is in environmental issues, like excess nitrogen applications, the more appealing this technology will be. I don’t want to be in a game where I’m so conservative on nitrogen that I reduce my overall profitability.”
Fulton Farms Ltd. - Shellbrook, Sask.
Grant Fulton operates Fulton Farms Ltd. with his brother Roger. The operation produces spring wheat, canola, peas and malt barley on 2,800 acres of cropland near Shellbrook.
“We were looking at variable rate fertilizer, but the companies that are doing that are quoting ten dollars an acre for prescriptions. They’re using NDVI maps from satellites, plus soil testing separate zones, then writing prescriptions. I’ve been watching the Greenseeker technology for a while thinking that looks like the way to go,” says Grant.
“What it’s going to do for us is give us an NDVI reading in real time, as we apply our top dress fertilizer. To me, that’s the time you want to know how much your crop requires, rather than try to get into expensive variable rate equipment. I haven’t been sold on the fact that anybody has a firm grasp on these prescriptions.”
The Fulton’s land is quite variable, with lots of topography and soil types. But even on land that doesn’t have excessive topography, Grant says there’s still a lot of difference in the yield maps.
“We’re hoping we can even off our production by putting the fertilizer where it should go. We’ve got a lot of sloughs, small fields and overlapping of fertilizer applications over the past few years. I think it’s going to answer a lot of questions we have,” he says.
“For example, we grew an 83-bushel crop of peas last year. This machine should tell us, in the wheat where we normally put 70 pounds on and we only put down 40 pounds, if we’ll see benefits from last year’s peas. I think it’s going to be a wonderful tool to help us address the application of expensive fertilizer.”
Fulton plans to put on two-thirds of the regular nitrogen rate this spring.
“We normally put on 100 pounds of N with our Liberty Link canola hybrids, so we’re planning to put on 70 pounds of N at seeding,” he says.
“We use liquid, sidebanded with a Seedmaster drill. We’ll have our sulfur, phos and N in that blend. Then we’ll go out and apply whatever extra nitrogen the crop tells us it requires, through the Greenseeker system.”
Fulton said one concern with their system is they couldn’t just vary nitrogen. All three – N, P and S - are blended and carried in one tank.
“If we varied that rate, we’d be varying the rate of everything. With this, we’ll have variable rate just with the top dress nitrogen,” he says.
“It makes sense with us on our farm. We’ve got a big sprayer that can easily handle twice the acreage we have. I’m not concerned about having time to get the top dress on. You have to have the capacity to cover all your ground again, after you’ve sprayed your herbicide.”
Fulton owns a Sprayair Predator, with a 1,000-gallon tank and a 103-foot boot, so he can get some acres done in a hurry.
“We already own the sprayer, so it’s more labour and fuel. I think we’re in a good position to make economic use of this system.”
Fulton adds he plans to aid the research Guy Lafond and Chris Holzapfel are doing. He’ll give them his yield maps and any data he can collect.
“I’m probably going to do some different things, as well. I might do part of a field with the full 100 pounds of N, do part with the 70, do the variable rate application on it after and maybe top dress some with the full rate, up to the 100 pounds, then check the yield maps to see how it goes. I like to do experimenting myself,” he says.
Fulton is looking at other uses for the technology, as well.
“Every time we cross a field with the sprayer, we’ll be doing an NDVI map of the field. It should help us make other decisions,” he says.
“If you run it through the crop at flag leaf, you can get a close reading for the yield, if you’re considering fungicide applications. It will tell you if you’ve got the yield potential to make a fungicide application worthwhile. So it’s probably going to have more uses available, as we get to know how it works better.”
There’s also the environmental aspect of it. Fulton says every decision they make on their farm includes an environmental aspect to it. If this can eliminate any over application of nitrogen, there’s both an economic and an environmental benefit.
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