Do you think your biggest challenge in designing your direct seeding system is how to apply the nitrogen fertilizer? This is one of the most commonly asked questions.
However, it may not be because there are too few choices -- quite the opposite. The bigger question is first, what's your goal? And, what will the rest of the system include? As we often say, it all has to work together in a direct seeding system.
Crop safety should be one of your goals. Cereal crops are much more forgiving than non-cereals. Maintaining an excellent seed bed should also be of paramount importance. What is more important to you -- getting the seed into a firm, moist seedbed or placing the fertilizer in the ideal place? If both are equally important, you will be more limited in your choices of equipment. The ideal placement of nitrogen fertilizer is still 1-1.5 inches to the side and 1-1.5 inches below your seed.
The next question may be -- for simplicity sake, can I apply all of my fertilizer down in the seed row? There are bulletins which will help you to decide whether or not it is safe for your crop. In some circumstances you may be able to accomplish it, but with most of the non-cereal crops, it will be difficult unless your nitrogen requirements are very low, you farm wet clay soils, your row spacing is narrow, or your seed row width is wide.
So, what if I know I cannot put it all with the seed? Your next question may be, am I locked into a one pass seeding system or can I live with a two-pass system? There may be many reasons for choosing either approach, but if you did choose a two-pass system, there may be more choices than you think. Some are deep banding anhydrous in the fall, a traditional method with an inexpensive product for sure. Others, especially when thinking about this spring's harvest are wondering if there may be other ways to do it.
If you are wanting or restricted to two passes, you might a liquid N source and applying it after seeding with a spoke wheel injector or coulter system. A big advantage of these implements is that you have the opportunity to apply it after seeding and not disturb the seedbed nor the growing crop. In fact, they leave so little evidence of disturbance behind that you'll have a serious challenge in seeing where you've been unless you have a good marking system.
Some producers will broadcast urea or ammonium nitrate. The efficiency of this method would be lower down the list than other methods. This is especially true in a direct seeding system, where the N can get tied up by the surface straw residues, but it is still an option. Urea will be less efficient than ammonium nitrate, but more readily available on the market.
What about a one pass direct seeding system? This is a minefield to walk into. It seems that some double shoot openers are better than others in different conditions. Do you prefer one fertilizer source over another? There are advantages to each.
If choosing anhydrous, there have been studies by Saskatchewan Wheat Pool, Agriculture and Agri-Food Canada, Alberta Farm Machinery Research Centre, Ag-Quest, ConservaPac, Westco and PAMI which will say that it can be done! But, there are still many cautionary comments to make and it warrants a completely separate article to sort it out. It would be wise to look into all of the information before committing oneself. Many farmers have successfully applied anhydrous or urea with a double shoot system. All of the companies seem to be able to site examples of their openers being used in this way.
You could avoid the minefield completely and apply the fertilizer in a separate band. A coulter can be used in a mid-row band, sharing a row of fertilizer between two seed rows. Bourgault has adopted this approach, not wanting to commit themselves to designing a double shoot opener that will only work in certain conditions.
Yet another approach would be to mount a liquid kit to your seeder, strap on some hoses and dribble or squirt a liquid product. The hoses can be positioned so the fertilizer is to one or both sides of the seed row. Usually, you can design the system to mix the fertilizer with the soil in the furrow. This often means that the fertilizer is actually above the seed, rather than below or beside it. Those who adopt this method are more concerned with seedbed quality than ideal placement of the fertilizer.
How should you choose to fertilizer your direct-seeded non-cereal crop? Your goals come first. There's a multitude of ways of getting the fertilizer in the ground, the choice is up to you.