College News

Ag Instructor Vic Martin: Soils and Climate Change

Great Bend Tribune
Published September 16, 2023

The drought monitor report as of 8 a.m. Tuesday, September 12 shows no change for our area this week.  However, the western third of Kansas slowly continues to improve, especially near the Colorado border.  Southwest Kansas has a large portion of the area completely out of even dry conditions.  The six to ten-day outlook (September 19 to 23) indicates a 40 to 50% chance of leaning above normal for temperatures and a 40 to 50% chance of leaning to above normal precipitation.  The eight to fourteen-day outlook (September 21 to 27) indicates a continued 40 to 50% chance of above normal temperatures and normal to a 40 to 50% chance of above normal for precipitation.  Definitely a more favorable forecast for planting the 2024 wheat crop.   Above normal temperatures likely means the mid to upper 80s.

The last several weeks, this column has discussed climate change.  Today, what are the possible effects of climate change on the soil environment?  Keep in mind that we are now living in the Anthropocene Epoch.  In English, the age where humans are the predominant force on the landscape.  So, as we discuss the effects of climate change on the soil environment, keep in mind we can modify or ease many of these effects through proper management.

  • As precipitation extremes become more frequent and severe, from extreme drought to torrential rains, combined with extreme wind events; wind and water erosion potential increase on cultivated soils.  We lose the most productive fraction of the soil – clay and see a decrease in soil structure.  The effects can be lessened or even eliminated through decreasing tillage, maintaining surface residue cover, and practices such as cover crops and terracing.  It would also be beneficial to take our poorer, less productive soils and put them into native vegetation.  Here that would be mixed grass prairie and this acreage could be used for cattle.
  • Drier, hotter soil conditions lead to a decrease in the accumulation of table organic matter.  There are two reasons.  During periods of extreme drought, less vegetative matter is produced and with hotter conditions the organic matter decomposes more quickly.  As we reduce or eliminate tillage, we aid organic matter accumulation.  Surface cover helps cool soils and decrease evaporation.  Where possible, cover crops also help.  Stable organic matter is a key in good soil structure as well as water and nutrient holding capacity.  The development of soil structure, especially continuous macropores is essential in limiting runoff during extreme rainfall events and increases water infiltration.
  • Finally, hot, dry soils (especially dry) play havoc with the microbial community and macroinvertebrates such as earthworms.  These are key to good soil health and crop production.  The decompose organic matter, recycle nutrients, and some are in symbiotic relationships with crop plant species.

There are other effects.  What we need to do is understand is we have a choice.  We can fight against nature and the climate or learn to work within it.