As temperatures go up and the weather begins to feel more like spring, it is the perfect time for Iowa farmers to focus their attention down by investigating their soil. If farmers dig a little, they can learn a lot by simply smelling, feeling and looking at their farm's most important production asset.
"It doesn't matter if you operate a large or small farm, grow organic crops, or if you're simply a homeowner or gardener who wants healthy, productive soil. It's easy to examine your soils," says state soil scientist Rick Bednarek with USDA's Natural Resources Conservation Service in Des Moines. "Take a quick look and you can learn a lot."
To investigate your soil's health, simply use a digging tool such as a garden spade or shovel, and your eyes, nose and hands to look, smell and touch.
* LOOK—Check for plant residue on the soil surface and a living canopy or cover. The soil structure should look like chocolate cake with air holes permeating throughout. You should see earthworms, organic matter and live roots that extend deep into the soil.
* SMELL—Healthy soil should have a sweet, earthy aroma of geosmin, which is a byproduct of soil microbes called actinomycetes.
* TOUCH—Soil should be loose and crumble easily. In healthy soil, roots can grow straight and deep, allowing plants to reach needed nutrients and water.
There are a number of reasons why farmers should strive to have healthy soil
Soils damaged by disturbing activities like tillage or continuous grazing damage are typically lighter in color with a more flour-like consistency and less color diversity. Unhealthy soils typically feel heavier than healthier soils, but they will break apart much easier in your hands.
Why should you care about soil health? According to Bednarek healthy soil provides an abundance of benefits. Healthy soils: sustain plant and animal life, filter potential pollutants, cycle nutrients, hold more water which reduces flooding and helps with drought, resist runoff and erosion, and naturally suppress weeds and pests.
To learn more about improving soil health visit the NRCS website.
Say 'no' to spring tillage: Is that tillage trip really necessary? How much soil moisture is lost by doing tillage?
Spring tillage is a tradition steeped deeply in American agriculture. But more and more farmers are realizing that this iconic tradition is costing them -- in more ways than one.~~~PAGE_BREAK_HERE~~~
Tillage comes at a high price. There are the known expenses like increased fuel and labor costs. But according to Bednarek, the bigger, long-term cost may be the loss of soil health and function resulting in lower yields, higher input costs and reduced drought resiliency for Iowa farms.
"Tillage is incredibly destructive to the soil structure and to the soil ecosystem," says Bednarek. "Healthy soil is 50% air and water which is made possible by the pore space in the soil and 50% mineral and organic matter. But tillage collapses and destroys that structure, making the soil vulnerable to erosion and compaction."
Tillage destroys soil structure, making spoil vulnerable to erosion, compaction and runoff
The possibility of another dry year should also have producers rethinking their use of tillage, says Bednarek. "Because it destroys organic matter and soil structure, tillage actually reduces the soil's infiltration capacity," he adds. "Studies have shown that each tillage pass can release a half-inch of soil moisture from each acre. Tillage tends to limit the availability of water in the soil and that could prove very costly during those long, summer dry spells."
Fortunately, more farmers in Iowa are farming with systems to build soil health. "Using a suite of conservation practices, like no-till, nutrient management, and cover crops," he notes, "they're keeping living plants in the soil as long as possible and they're keeping the soil surface covered with residue year round."
Increased water holding capacity of soil reduces runoff, which helps minimize nutrient pollution of streams, ponds and lakes
The benefits of improved soil health extend beyond the farm. "Farmers who improve the health of their soil are also increasing its water-holding capacity, which reduces runoff that can cause flooding. Improved infiltration of water into the soil in the field keeps nutrients and sediment from being carried off-site into nearby lakes, rivers and streams," says Bednarek.
Farmers who are interested in learning more about the basics and benefits of soil health or receiving technical and financial assistance to implement a soil health management system, should contact their local NRCS office. Additional soil health information is available here.