The drought monitor report as of Tuesday, August 23, indicates increasing expansion of severe drought. Nothing more needs to be said. Currently the outlook for establishing and maintaining the 2023 wheat crop is sketchy at best for many parts of Kansas, with exceptions scattered about. The six to ten-day outlook (August 30 to September 3) indicates a 33 to 40% chance of above normal temperatures and normal to a 33 to 50% chance of above normal precipitation (our area is right on the line). The eight to fourteen-day outlook (September 1 to7) indicates our area is right on the line between normal and a 33 to 40% chance of above temperatures and normal precipitation (the long-term average monthly precipitation is only about two or so inches). Today, with the summer we have had and the outlook through the winter, why soil testing matters now than ever.
This column has discussed the value and importance for developing a soil testing program for crop and pastureland. In years like this, with much of the area’s crop significantly impacted by drought and high temperatures there is a temptation to skip it because of the time and expense or because a producer figures the fertilizer placed down earlier is still there. What is the answer? Please keep in mind that there is a standard soils test for items such as pH, potassium (K), phosphorus (P), etc. and a different test for both nitrogen (N) and sulfur (S).
• If a field hasn’t been samples in several years, a soil test needs to be performed in any case. As far as much of the applied fertilizer still being there, it likely is but it may not be in an inorganic form. Remember many fields had poor to fair vegetative growth so nutrients were taken up. With poor seed production, some is likely in an inorganic form in the soil. Some is in the vegetative crop growth. That fraction will only return to the soil in a usable inorganic form as the residue (above and below ground) decomposes. That takes microorganisms to beak it down and they need soil moisture and decent soil temperatures. This is true of nutrients such as nitrogen but also phosphorus, potassium and others.
• There are fields, especially corn but also soybeans and sorghum, where producers have removed all the above ground vegetative matter for hay and/or silage to try and at least obtain some useful crop. That will remove, in many fields, residue that normally would have released certain nutrients such as K and calcium.
• If producers are concerned with soil acidity, mostly south and southeast of Great Bend, and have applied lime, and are considering planting alfalfa this fall or next spring, moisture permitting, it takes months to a year for the ag lime to neutralize acidity under normal conditions. With this lack of rainfall, the lime may have reacted little.
• Finally, know what you have saves you money. First, not applying what you don’t need to applying. Second, if you need it and hopefully moisture conditions improve over the next nine months, you are losing money with insufficient fertility.
Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207, or firstname.lastname@example.org.