GreenSeeker keeps nitrogen in balance

Sometimes less is more | GreenSeeker reads the leaves and puts down the appropriate amount of nitrogen for max yields

It’s not often that farmers can invest in a piece of farm equipment that makes them money while sitting in the shed.

And when they do drag it out to the field, it sometimes does nothing at all, except save them more money.

But that’s the way the GreenSeeker increases profits, says producer Lee Moats of Riceton, Sask. It tells farmers not to do something that they were planning to do: apply nitrogen.

“The best thing the GreenSeeker did for us in 2011was stay in the shed so I wouldn’t be tempted to top-dress nitrogen,” Moats said.

“I put down our usual low rate of 40 pounds nitrogen when I seeded and didn’t put down a single pound after that. Normally I do a split application to top up the crop. But not in 2011.

“I did actually take the GreenSeeker out of the shed and ran it over some crop just to see if we needed more nitrogen. It told me zero N everywhere I drove, so it went back into the shed and stayed there. It had done its job for the year.”

Skipping his typical in-crop split nitrogen application saved Moats $25,000 in fertilizer costs for 2011, which is about what the machine cost him in 2009. He called the machine an excellent investment, giving him similar sound advice since 2009.

The six-sensor device is mounted on a CaseIH SRX with a 100 foot-boom. Moat uses the same sprayer for herbicides and simply switches to dribble banding nozzles for liquid nitrogen.

Although he had been studying the GreenSeeker for a number of years, Moats said 2008 was the clincher. Spring was dry and he had a lot of winter wheat in the ground.

The only winter wheat that survived was the crop that received 100 pounds actual nitrogen in the fall. He said that wasn’t necessarily good news because, even with all the nitrogen, it yielded only 26 bushels.

“We had invested enough N for a 70 bu. per acre crop,” he said.

“The nitrogen ended up just sitting there, not working for us. That in itself is expensive, plus you run the risk of losing nitrogen to the environment. If we’d had a GreenSeeker in 2008, we wouldn’t have put down 100 lb. at seeding, and in the spring it probably would have told us to skip the nitrogen all together. That would have saved us a bundle of money. So that got our attention.”

Moats said 2009 was a tremendous year for moisture in his area. He had assumed the machine would tell him to put down little or no nitrogen in dry years and lots in years with good moisture. He figured that’s how it would maximize profit potential.

“Turns out that so far it hasn’t worked that way at all,” he said.

“In our canola in 2009, the Green­Seeker called for very modest amounts of nitrogen, about 65 lb. on average. That’s about two-thirds what we normally put on.

“We had put down 40 lb. while seeding. When we did the in-season application, we had trouble believing the machine. It called for zero N over large tracts of canola and 25 lb. plus on other areas. But the field average was only 25 lb.

“Farmers always like to talk about their best crop. Well, our InVigor averaged 63 or 64 bu. When I work the nitrogen balance, we simply cannot grow that crop with the modest amount of nitrogen we put down. But we did.”

Moats said it was a significant cost saving in a year when he expected to buy a lot of extra nitrogen.

His 2010 canola crop was a similar story. Following instructions from his GreenSeeker, Moats applied 60 lb. of nitrogen per acre, and the canola eventually yielded 55 bu.

“Most of our fields have been in zero till 20 years or longer. They’re mineralizing a lot more nitrogen than we anticipated,” he said.

“As a result, our GreenSeeker has been saving us nitrogen in years when we expected it to call for more nitrogen. I think that speaks to our overall soil health.”

“What could be better for your pocketbook than spending less money on inputs while maintaining high yields? And it’s better for the environment as well.”

Moats said there’s more to the environmental aspect than meets the eye. Sustainability is becoming a real factor in the food industry.

It may be nothing more than public image and window dressing for the major food companies, but the fact is they are looking at the environment in which crops are grown. That includes nitrogen management, which is the major component of the carbon footprint.

“It’s not out of the question that companies will someday pay farmers a premium for food that has a documented clean green history,” Moats said.

“GreenSeeker, of course, lets us reduce nitrogen and then provides us with data to prove it. For example, the canola calibrations from (the) Indian Head (Experimental Farm that analyzed a test field) are so good, we simply cannot find fault with them. They are based on western Canadian soil and climate.”

Moats said that he still has reservations about the calibrations for durum, even though his first Green­Seeker experience with the crop in 2009 produced high protein along with high yield.

“Until 2009, we had never sold a bushel of high protein durum off this farm. Ever. You just know the machine is doing a good job when all of a sudden you get protein running from 13.9 percent to 14.3 percent. We had one field that was uniform protein on every load.

“But in 2010, we were sure we had under-applied nitrogen on durum. And this time we were right. Protein and yield were down, but just slightly. So the GreenSeeker had not performed as well as in 2009.”

Moats said it’s important that the calibrations and growth degree days entered into the computer be spot on. If they’re off, the machine has no way to compensate for it.

“Winter wheat remains the one crop where we really don’t trust the GreenSeeker yet,” he said.

“If we depend on the machine’s opinion, we’re concerned the winter wheat doesn’t get enough nitrogen early enough in the growing season.”

Moats said it’s a time issue and a calibration issue. GreenSeeker calibrations for each crop are tied to the amount of heat it has received, as measured in growing degree days (GDD).

Winter wheat is seeded in the fall, so GDD calculations are skewed from the start. Calibrations for winter wheat GDD do not relate to spring wheat GDD because the winter wheat was already actively growing eight or nine months before the spring wheat was seeded.

To use the GreenSeeker properly, Moats said it’s also necessary to understand the difference between plant growth and plant development.

“Plant development is highly related to heat,” he said.

“Heat is what brings it through the stages. One, two, three, four leaf stage. Plant growth, on the other hand, depends on access to nutrients and moisture, plus heat.”

For example, a drought challenged plant may have less foliage material, but it’s at the same development stage as other healthier looking plants.

Moats said the GreenSeeker must be programmed to know that it will be dealing with smaller plants that are already at the correct stage of development for in-crop nitrogen.

“The GreenSeeker needs all that information so it isn’t fooled by thinking a plant is at a different stage. It must know for sure what stage the plant is at. And that information comes from the farmer who owns the machine.”

Most of the GreenSeeker calibration work in Western Canada has been performed by Guy Lafond and Chris Holzapfel at the experimental farm in Indian Head.

They have conducted numerous trials on many crops to calculate the response to different nitrogen levels. They relate that data to the Normalized Differential Vegetation Index to come up with an algorithm that drives the calculations within the GreenSeeker.

Calibrations developed for crops in the United States will not work on the Prairies because of differences in hours of sunlight, heat, soil and latitude.

Moats said Lafond and Holzapfel now have good calibrations for spring wheat, canola and barley, but winter wheat needs refinement because they can’t use the normal GDD to determine stage of development.

The researchers have also developed new algorithms specific to different soil types on the Prairies. Their algorithms for the dark brown soil zone are different than those for the black soil zone.

“You’ll get very good results on spring wheat, canola and barley just as long as you go in at the appropriate stage,” he said.

“That’s the key. Get yourself out there with your GreenSeeker at the stage that’s appropriate for the algorithm. If you’re too early or too late, it won’t work.

“The machine can’t do everything for you. You are responsible for keeping track of your own GDD information. And you have to make sure you’re within the range of growth stage the algorithm is designed for.”

Canola is a good case study. The crop will have too many blossoms and confound the sensors if producers are late getting into the field with their GreenSeeker. If they’re too early, the algorithm isn’t geared for that stage.

“You have to get within a fairly small window if you expect it to work. You’ve got to be right on top of things feeding it the right information.”

Moats said farmers’ personal opinions about nitrogen efficiency also influence how they use the machine. A GreenSeeker owner who thinks nitrogen efficiency will be really high in a given year will program the machine to back off on the rates.

He also questions whether Green­Seeker owners have any way of knowing if the device is working to its full potential. He said that even after a successful harvest, there is no way for him to know how much more crop could have been grown with the same or less nitrogen.

“It’s so sensitive to N requirements. You’re riding down the field and you cannot visually see why it’s calling for more or less N. The variability within one field can be zero to 60 lb., but we cannot see why.

“We have absolutely no way of knowing if it can do a better job for us. All we know is that it increases profits. The true potential really remains a mystery. You just have to believe in the technology, because it works.”

For more information, phone Lee Moats at 306-738-4716 or visit

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