Feb 05, 2023

Barton Ag Instructor Dr. Vic Martin - Evaluating Soil Health

Posted Feb 05, 2023 9:00 PM
<b>Barton Community College Agriculture Instructor Dr. Vic Martin</b>
Barton Community College Agriculture Instructor Dr. Vic Martin

The drought monitor report as of Tuesday, January 31 indicates no change even with the precipitation received.  Approximately 75% of the state is in moderate to extreme drought with the worst conditions in the western half of the state into South Central and much of extreme Southeast Kansas.  Again, there is little hope for any change in our area’s conditions in the short or even long term.  The six to ten-day outlook (February 7 to 11) indicates a 40 to 50% chance of above normal temperatures and 33 to 40% chance of above normal precipitation.  The eight to fourteen-day outlook (February 9 to 15) indicates a continued 40 to 50% chance of above normal temperatures and a continued 33 to 50% chance of above normal precipitation.  We are slowly seeing the precipitation chances increasing, even if slightly.  And with the projected temperatures, wheat should soon start to break dormancy.  In case you are wondering how accurate the outlooks by the Climate Prediction Center.  The have been pretty spot on the last year.

Whether a producer is dealing with drought or saturated soils conditions, a major key is the health of the soil the crops are growing in.  This may seem a bit strange when considering we view soil as a nonliving organism.  So, what factors are considered regarding soil health, and what makes for good soil health?  Today, let’s briefly consider factors determining soil health and what makes for good soil health?  This will somewhat change depending on the plants involved.

·       The bulk density of the soil, how much it weighs per unit volume.  This tells you how much of the volume of the soil is taken up by solids (minerals and organic matter) and how much is space.  Ideally, the topsoil and immediate subsoil should be 50% solids and 50% space.  The solids should consist of 45% mineral fraction and 5% organic matter.  The 50% space should be 25% air and 25% water.  A bulk density that is too high or too low results in a poor soil environment.  In case you’re wondering. A bulk density of 1.2 – 1.5 grams/ cubic centimeter is the “ideal” range for most crops.

·       Having a good mixture of interconnected micro- and macro- pores.  The micropores hold water and the macropores are responsible for gaseous exchange and water movement.

·       A crumbly soil structure is ideal and it indicates good porosity and ease of root penetration and good root growth.  It also indicates decent to excellent organic matter content.

·       To hold water and nutrients as well as to promote good soil structure, an organic matter content of 5% or a little higher is ideal.

·       For most crop plants, a soil pH reading in the range of 6.2 to 7.2 is ideal.  This allows for good nutrient availability, minimizes the chance for toxic levels of certain elements, and promotes the presence of beneficial micro flora and fauna, especially bacteria.

·       Finally, for today, a healthy, active microbial community that promotes recycling of nutrients and breaks down organic matter producing humus.

As is typically said, there is more, but this provides a basic idea of what to consider.