Healthy soils can be a crops’s best friend when the weather turns extreme.
If it’s too dry, a healthy soil with high water-holding capacity can capture, store, and deliver critical moisture to growing plants; if it’s too wet that same soil will play a key role in transporting excess water down through the soil profile to protect both the plant and valuable soil.
On this episode of RealAgriculture Soil School, host Bernard Tobin is joined by University of Minnesota assistant professor and soil health extension specialist Anna Cates to discuss and define ‘healthy soil’, what agronomic practices contribute to it, and how it holds and moves water in dry and wet environments.
Cates says a healthy soil system is one that keeps the soil covered, minimizes disturbance, includes crop diversity, keeps living roots in the ground and integrates livestock. “So the way we do that when we’re mostly growing corn and soybean as cash grain crops is we add cover crops, we add a third crop in rotation and we reduce tillage — from full width disc ripper chisel plow-type systems to strip-till or no-till situations.”
Cates says this management approach essentially allows farmers to tap into the power of soil biology. “Instead of doing tillage to create pores and fluff up the soil for planting, you use roots to create pores, and you let the biology in the system mineralize nutrient and live in those pores and structure that you provide.” (Story continues after the video.)
For the past three years, Cates has studied how soil can hold more water in drought conditions. The key, she says, is soil pores — both big and small.
“That’s why clay soils are really good at holding water because they have a lot of small pores,” notes Cates. “But the other function we want in soil is for water to enter. We need big pores for water to enter and to get down deeper in the profile. We don’t want to hold all of our water in just the top six inches or 10 centimetres, we want to get deeper. And when you have good soil structure and soil aggregation, then you have both big and small pores.”
In the video, Cates discusses how cover crops and plant roots play a role in water management and movement. She also has some tips for farmers on how to assess their soil health. You can learn a lot in the middle of a rainstorm.
“If you’re driving home in the rain, and you’ve got your boots in the truck, go see what’s happening,” says Cates. “Go see whether the water is going in or whether it’s not and that’ll tell you whether your soil is healthy enough to respond to the rain you’re getting.”
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