Create drought-resilient soil
Dale Strickler, farmer and Agronomist at Green Cover Seed, addresses the question of what to do about drought at the fifth annual South Dakota Soil Health Conference.
Strickler says improving the drought tolerance of soil is simple in theory but much harder in practice.
Increase Water Infiltration
The first step is to increase infiltration. “Of all the steps, if you mess up this first one, you’re in trouble,” Strickler says.
A lack of infiltration is one of the biggest problems facing farmers and the environment because when water fails to go into the soil, it runs off. When it runs off, it causes problems elsewhere, like flooding and nutrient loss.
“One of the greatest inventions of all time is a rainfall simulator because it dispels a lot of myths,” Strickler says.
Rainfall on tilled soil breaks apart loose aggregates, seals and creates a crust that acts as a barrier to water. This type of tillage practice results in the most runoff.
To better drought-proof your soil, add mulch. If you don’t have mulch or residue, Stickler recommends growing it – in other words, planting cover crops. Living roots in the soil sustain soil microbes and create an environment for worms and insects to live and break through compacted pores, opening it up to soak in water.
“The more residue, the more infiltration,” Stickler says.
“One of the ways water is lost is by evaporation. And how do you stop evaporation? By addressing one of the factors that increases it: wind speed,” Stickler explains.
He recommends slowing the wind at the soil surface. One way to do this is by incorporating and preserving windbreaks.
“The reason some people take out windbreaks is the reduced yield of crop right next to it,” Stickler says. “But what they don’t see is that a higher yield decrease actually occurs further into the fields without a windbreak.”
Snow catch in stubble is another way to slow evaporation. The stubble (or mulch) helps retain moisture on the surface and does so for a longer period of time.
Additionally, residue on your fields takes up space weeds could normally grow, it reduces soil erosion, and can provide habitat for wildlife.
Increase Root Depth and Efficiency of Roots
“The more organic matter you have in your soil, the more its water holding capacity increases,” Strickler says.
One way to increase organic matter is by planting perennial crops, which Strickler says is how to really get serious about improving your soil’s drought resilience.
Perennial crops’ roots extend deep into the soil and by living 12 months out of the year in the field, can compound their benefits far more than annual crops.
Strickler also recommends incorporating a diverse mix of crops to build organic matter. “With deep taproots, forbs, fibrous grasses, shallow-rooted plants there is layering of leaves that use carbon dioxide and sunlight better in their growing environment and at different times of the year.”
A mix of plants will also introduce a variety of chemical profiles, which incorporates more nutrients and boosts the microbial biomass.
“You can change your soil. You can fix your soil. And you can make it drought resilient.”