Spend or save on fertilizer this year?
Simplify your decision with these recommendations
If you’re thinking about how you can save your way to prosperity this year, no one would blame you after a rough growing season and a winter fraught with grain delivery challenges. But it probably won’t surprise you to hear that I’d like to alter that thinking – at least a bit.
It’s widely accepted that 60% of a crop’s yield comes from nutrition. So I think that’s the best place to start, especially if you’ve already spent good money to get the genetics inside bags of seed. You can take your lead from the 4R approach to make the most of your fertilizer dollar.
First, take a look at your soil test results. These will show you where you have nutrient deficiencies that could be limiting yield. If you don’t already have one in hand you may run out of time to get one in the spring. If that’s the case, calculate the net nutrient removal of the crop you plan to grow, and aim for sufficiency. (Right rate)
The most commonly overapplied nutrient is nitrogen, which causes lodging in wheat and barley, and high protein in barley and pulses.
Overapplying N also leads to off-gassing and/or leaching before the crop can use it. No one wants to watch dollars invested in fertilizer running off their fields.
Also, if you’ve got pulses in the rotation, rhizobium symbiosis allows these crops to fix N from the soil atmosphere, making extra N unnecessary.
Spend or Save? Altering your rotation plan will help you save. Use those fields that are high in residual N to grow canola yield or increase wheat protein. Grow pulses on fields that are low in residual N. Ensure you use adequate volumes of inoculant and let the bacteria do its magic. On pulses the wise investment is inoculant, not more N.
On the other hand, phosphorus is often under applied. Crop genetics are getting better every year, and we’re seeing higher yields but not always applying what we should to replace nutrients taken up by those huge crops.
Soil tests also give you a more complete picture of your soil, including pH and organic matter. When you look at this all together, you begin to understand what you should apply. I have learned that most Saskatchewan soils have a high pH (>7). At a pH of 7.5-8 you begin having issues with low availability of P and some micronutrients.
Because of the soil’s constant fight to render phosphate unavailable, you want to get it as close to the seed as possible.
The same rule applies with most nutrients. I’d rather put nutrients close to the roots so they can be taken up into the plant.
That’s why I recommend you rethink foliars. Under dry conditions the crop will close stomatas to protect its moisture. Then if you get rain, it will wash the micronutrients onto the soil. Foliar applied nutrients are not a stress relief product. Rain is a stress reliever.
If you do decide to go for it, spoon feed your plants at critical times during the growing season instead of looking for a one and done approach.
Spend or Save? The right spend is to put your nutrients where they will most likely be available and used by your crop so you’re not just hoping for uptake. (Right place)
Sulphur readings in a soil test can also be inaccurate unless you consider the whole picture. For example, in high salinity situations, the soluble salts are high, which might trick you into thinking you have a good amount of S. However, only when soluble salts are low and S is high, is there true S sufficiency.
Spend or Save? Choosing a fertilizer with low pH like MicroEssentials® S15® and MicroEssentials S10®, which has half elemental S and half sulphate is a wise spend. This means the sulphate is available for early season growth, and the elemental S becomes available because of oxidation through the growing season. (Right source)
If you broadcast urea this spring, use an inhibitor like Agrotain® which protects against volatilization. Nitrous oxide is the most impactful greenhouse gas, and spring melt makes for anaerobic conditions, which are perfect for nitrous oxide emissions.
That said, if you can drive on a field, anaerobic conditions don’t. With ammonia volatilization is more of a problem so use a mid-row or side bander in spring. You won’t need an inhibitor product in these conditions.
In northern Saskatchewan the practice is to perform anhydrous deep banding, which dries out the soil, whereas closer to Saskatoon and south they don’t want to dry out because water is a very important factor.
Spend or Save? By mid-row or side banding you can save money on inhibitor but spend on diesel fuel and time. Time is critical in the spring, because the more time you take to finish seeding the less moisture you potentially have for the crops seeded last.
If you’re looking for ways to stretch your fertilizer dollar this year, contact your nearest Cargill location for insights on the best ways to save or spend.
MicroEssentials is a registered trademark of The Mosaic Company. Agrotain is a registered trademark of Koch Agronomic Services LC.