College News

Ag Instructor Vic Martin: Crops and the Goldilocks Principle

Great Bend Tribune
Published August 21, 2022

The drought monitor report as of Tuesday, August 16, indicates more severe drought conditions are moving eastward and into Barton County with little hope for significant rain in the forecasts.  Only the Northeast Kansas corridor is in good shape and that is shrinking rapidly.  The six to ten-day outlook (August 24 to 28) indicates a 33 to 40% chance of below normal temperatures and a 33 to 50% chance of above normal precipitation.  Nice, but not enough to make real difference for our summer crops with maybe the exception of grin sorghum.  The eight to fourteen-day outlook (August 26 to September 1) indicates continued chance of below normal temperatures and a 33 to 40% chance of above normal precipitation.  Today a brief discussion of the Goldilocks effect on crops.

Why bring this up?  Crop plants are bred for a given environment.  We can modify them to produce economic yields outside of where they would normally thrive.  However, we sacrifice potential yield when we do so.  Whenever you modify a plant, an example would be cotton varieties available today that can consistently produce economically viable yields as far north as Barton County most years, we have had to give up potential yield and fiber quality.  So even though we can significantly tweak them, there is a range of conditions for each environmental variable for crops to be economically viable – the Goldilocks Principle.

We all know the story of Goldilocks and the Three Bears.  Where she selected a bed that wasn’t too soft or too hard but just right and so on.  Earth isn’t too close or too near the sun so it can support life as we know it.  This principle applies to crop production and applies to everything from soil moisture, air temperature, and humidity to nutrients.  Typically, they are referred to in crop production as “cardinal” amounts.  Use air temperature as an example.  There is an optimum air temperature range, the cardinal optimum, where a plant will thrive.  As the air temperature increases or decreases from that optimum, you enter stress zones.  Moving too far above or below and you find the cardinal maximum and minimum respectively.  Surpassing those extremes normally results in the death of the plant.  Being near the extremes for any period of time may not kill the plant but results in significant yield reduction. 

Producers try to work with the extremes of the average cropping season to the best of their ability.  For example, delaying planting in the spring until the greatest danger of freezing temperatures is over.  Planting corn as early as possible and selecting an earlier variety to have it tassel and silk before the worst heat and moisture stress.  There are probably many examples producers can think off.  And with some exceptions such as the twenty-year drought cycle, producers are pretty good at this weather permitting.  But there is a rub.

Weather patterns are becoming more extreme and unpredictable.  If it were a case of shifting weather patterns but occurring in a fairly repeatable, predictable manner, it would be easier to adapt and try to work around.  The trouble is we don’t know if this is going to be repeatable or not.  The other challenge is the degree of the extremes.  It may sound weird but our highs and lows are becoming higher and lower.  We are seeming to be moving beyond the cardinal maximums and minimums on a more regular basis and that is hard to overcome as of now.