By Darren Hefty

If you’re raising a grass family crop this year, you need to have the proper nutrients accessible to that crop all through the season. The best way to monitor how plants are doing and to make adjustments to your fertility program as you go throughout the season is to pull plant tissue samples on a regular basis. Here is the plan we utilize on our farm and how we sort out the data to help us save money on fertilizer and earn more profit.

  1. Start by picking a good area and a bad area of one field. For advanced plant tissue test operations, you can pick however many fields you’d like to watch this season.
  2. Pull plant tissue samples each Monday morning for 10 to 12 weeks starting a week or two after emergence.
  3. Compare the good areas of the field to the bad areas and work to determine why the good is so good and why the bad is bad. What can be done to improve both areas, especially the bad ones?
  4. Chart the results for each nutrient and look for trends. Nutrient values may move up and down as rainfall events occur, which necessitates the duration being much longer than just one sample to get a true picture.
  5. Consider sidedress/foliar applications, but only as a supplement to a good soil fertility program. It’s difficult to make up for severe deficiencies and to catch them before they rob a ton of yield.
  6. Adjust your fertility plan for next year according to the trends you see on your plant tissue analysis.

I’ll give you an example of how regular plant tissue analysis has changed our operation. Years ago, we would look at our crops throughout the season, think they looked pretty good, and be disappointed each fall when yields weren’t what we expected. We would talk about why our yields weren’t as good as we thought they should be; and with corn, our answer was usually, “Well, I guess we just need more nitrogen.” We would add more N, and yields still didn’t go up. Thanks to plant tissue analysis, we learned our rudimentary diagnosis was completely wrong. Potassium, boron, and zinc turned out to be our biggest yield-limiting factors, so when we took some of our nitrogen dollars, stuck them into K, B, and Zn, our yields went up, and so did our profits.

I can’t say for sure what you’ll learn on your farm by pulling plant tissue tests. I can say with certainty spending 30 minutes a week pulling a handful of leaves and paying for a few $20 tests has been one of the smartest things we’ve done. For complete tissue sampling instructions on a variety of crops, look here.