By Brian Hefty

About 15 years ago, I started looking at research that showed a farmer could get by with approximately 30 percent less P & K when banding compared to broadcasting.  As soon as I heard that, I remembered my Dad always used to say, “Putting extra P & K on (when times are good) is like putting money in the bank.”  That may be true, but the problem is you may be putting it in someone else’s bank if you don’t farm that ground yourself for the next 50 years.

There are really two important questions here.  First, is it true that I can use less fertilizer when banding?  Second, how could that be true?

  1. Yes, it is true that banding can save you money on fertilizer.  There are numerous university and private studies that have proven this over the years.  We have also found this to be true on our farm on a large scale over the last decade.  Where we have broadcast fertilizer, we have applied 50 percent more P & K versus the fields where we have banded, and we have done that every single year for 11 or 12 years now.  In other words, we’ve spent a LOT more money on fertilizer on about 500 acres where we’ve done nothing but broadcast, while those fields, on average, yield no better than the banded fields.  Yes, our soil tests are going up a little more, so eventually we will probably see higher yields, but at this point we still have not.
  2. There are two main reasons why banding gives you better efficiency than broadcasting: placement and reduced tie-up.
    1. When it comes to placement, understand that roots aren’t that smart.  They don’t KNOW where you’ve placed fertilizer in your soil.  They simply grow based on the path of least resistance.  However, once they FIND a highly fertile area, they proliferate, putting lots of roots out in that area to absorb the fertilizer.  In other words, if you have a band of fertilizer where your roots will grow, odds are high the roots will absorb much of that fertilizer.
    2. Tie-up is a major issue with soil nutrients, especially when the soil pH is outside the range of 6.3 to 7.3.  For example, in high pH soils (above 7.3), it is common for excess calcium to bind with phosphate to form calcium phosphate.  Calcium phosphate is insoluble in water and can’t be absorbed by your crop.  In other words, you spent a bunch of money on phosphorus, and now your plants can’t use it.  That stinks.  To combat this issue, there are products like AVAIL, but there is also the cultural practice of banding fertilizer.  With fertilizer in a concentrated band, it is harder for your soil to react with all that fertilizer to tie it up quickly, especially in the center of that band.  Banding doesn’t solve the problem of tie-up, but it often lengthens the time before tie-up.

When is banding most likely to pay?  It should pay in just about all situations, but the return is even greater in high pH (over 7.3) or low pH (under 6.3) soils, high magnesium (over 25 percent base saturation Mg) soils, when applying non-mobile nutrients (P, K, and zinc, for example), and when fertilizer prices are high.  If you are going to band, doing a deep band or a 2 X 2 works about 100 percent of the time.  If you want to band in-furrow, be very careful with your rate and product selection.  Always use a low salt product and keep the rate low in-furrow.

If you are broadcasting, I’m not saying you are doing it wrong or that broadcasting can’t work.  I’m simply saying that banding fertilizer – especially P, K, and zinc – has been shown to require less fertilizer than broadcasting to get the same yield benefit.