Volume 40, Number 14 | SEPTEMBER 2, 2014
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PRACTICAL PRODUCTION TIPS FOR THE PRAIRIE FARMER
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SPLITTING THE DIFFERENCE Splitting your nitrogen application can decrease your risk. Find out if it’s the right fertilizer solution for your farm
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Some farmers using split nitrogen applications use GreenSeeker technology. The GreenSeeker system lets farmers apply nitrogen in-crop at variable rates during the growing season. BY ANGELA LOVELL
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s a split nitrogen application worthwhile on the Prairies? That’s a question researchers have been trying to answer for the past 30 years. The higher fertilizer prices rise, the more farmers want an answer. Is there value in hedging your bets — applying part of your nitrogen at seeding then waiting to see what yield potential the season brings before you add the rest? Or, is it better to gamble on having all the nitrogen the crop needs ready and waiting in case the weather keeps you off the fields when that in-crop application needs to be made? There has been plenty of research done in both Eastern and Western Canada and consequently there are differing opinions on the value of splitting nitrogen just as there are different cropping systems and conditions on either side of the country. The general consensus, however, is that there is no significant yield advantage from split nitrogen applications over applying it at seeding in most cases.
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THE WESTERN EXPERIENCE When you compare split nitrogen application to banding an equivalent amount of fertilizer at seeding, there is little yield advantage, says Cynthia Grant with Agriculture and Agri-Food Canada’s Brandon Research Centre. “Normally, our soils are dry enough and our season short enough that losses between fertilizer application and crop uptake are not enough to make split applications significantly better,” she adds. Dr Grant led multi-year research across various sites in Western Canada into crop yield with controlled release urea (CRU) and split application of nitrogen as compared to non-coated urea (NCU) just at seeding. The results showed that urea applied as an in-soil band at the time of seeding was generally as or more effective in increasing yield than use of a CRU, split application of urea or a blended application of urea plus CRU. The studies also found that delays in release of the urea from the CRU occasionally appeared to limit early season nitrogen avail-
ability and crop growth, resulting in some yield reduction versus non-coated urea, most commonly at sites where yield potential and nitrogen demands were large. “Across a wide range of ecoregions and growing conditions, the use of CRU or split applications do not appear to provide a consistent improvement in crop yield, nitrogen concentration in the grain, total nitrogen accumulation at harvest, or nitrogen use efficiency as compared to recommended applications of non-coated urea banded at the time of seeding,” says Dr. Grant. There are exceptions where split applications may have benefits: • Under wetter than normal conditions combined with warm weather which can lead to greater nitrogen losses in the spring; • When a high level of leaching has occurred due to lots of precipitation on light textured soils; or, • In variable rate situations based on nitrogen sufficiency using systems like the GreenSeeker that allow farmers to apply nitrogen rates to specific spots where deficiencies are identified.
A poor start to spring is another situation where split nitrogen might also be useful. If a farmer cuts back on fertilizer due to poor conditions in the spring, but the season then improves to the point where he expects a significantly higher yield potential than he first believed would be possible, adding extra nitrogen in-crop might help boost yields.
IN THE EAST The potential advantage of being able to add nitrogen in-crop to take advantage of improving weather conditions and increased yield potential is certainly supported by some of the research being done in Eastern Canada. Although when results are averaged over a number of years there is no consistent yield increase due to split nitrogen application, says Peter Johnson of the Ontario Ministry of Agriculture and Food. Johnson has conducted the research in conjunction with Dr. David Hooker, University of Guelph and found that, under certain weather conditions, split nitrogen applications
In This Issue
have been shown to increase yield in winter wheat in Ontario by seven to eight bushels per acre. All research indicates that the most important factor in whether split nitrogen applications improve or decrease yield is weather. “Split nitrogen applications have the potential to work very well but the weather plays a big role,” says Johnson. “The challenge with split nitrogen application is if a producer relies too much on the second application. For example if 120 pounds nitrogen total is the target and 30 pounds of nitrogen goes on up front, then most of the nitrogen goes on in the second application. If it starts to rain right when I want to put my second application on and I am delayed a couple of weeks, or if it doesn’t rain for two to three weeks after I apply the second shot — in both those scenarios I reduce my yield because I starve my crop for nitrogen in that two or three week time frame when the crop has high demand and I need the nitrogen to be there.”
» CONTINUED ON PAGE 4
Wheat & Chaff ..................
2
Features ............................
5
Crop Advisor’s Casebook
6
Columns ........................... 20 Cattleman’s Corner .......... 30 Machinery & Shop ............ 33
Floating fall fertilizer
DANELL VAN STAVEREN PAGE 14
AGCO’s tractor lineup
SCOTT GARVEY PAGE 36
FarmLife ............................ 44