World Soil Day 2020: What is the buzz about dirt?

Annually, Dec. 5 marks World Soil Day to bring awareness to the importance of this Earthly, life-giving substance. It serves as an international day to advocate for sustainable management of the soil. 

One of my college professors said that plants could grow without soil, but the soil cannot grow without plants. Do not worry. I know plants still need nutrients the earth provides to flourish, but without proper management, the ground cannot thrive itself. Understanding the soil around you plays a crucial role in ensuring it is being taken care of correctly. 

So, what does soil do? 

Soil Provides Nutrients. Plants need 17 essential elements to grow. Twelve of those nutrients come from soil processes. Carbon, oxygen, and hydrogen are 3 of the critical ones that help drive those processes. 

Properties of Soil / Photo courtesy of NRCS

Soil Holds Water. Water availability is crucial for plant growth. To put it into perspective, for 1 ton of soil, we need 200 tons of available water for optimal efficiency. Silt plays a vital role in the water holding capacity that the ground has.

Soil Participates in Gas Exchange. Above ground, this gas exchange includes photosynthesis, converting carbon dioxide and water into sugar and oxygen waste (what we use to breathe). Below ground, sugar is transported to the plant and dissolved in available water for the plant to use. 

Soil Acts as a Nursery. It promotes plant growth by providing a stable, safe, and friendly place for plant seeds to obtain nutrients before they emerge from the ground. For seeds planted under the surface, they have more protection from rodents looking for their next meal. 

While these are not all the roles that soil partakes in, they are essential to plant growth and productivity. If soil is not taken care of, its ability to function in these roles becomes inhibited. 

Dan Dietz, a crop and livestock farmer in Northeast Iowa, implements multiple measures to improve his land’s soil health. Half of the acres on his farm are dedicated to growing cover crops, letting them grow to maturity to improve biomass. 

Dan Dietz with his son, Drew, checking out one of their fields
/ Photo courtesy of Kayla Dietz

“Having a living root there all the time [is extremely beneficial],” he said, regarding the acres he uses to plant soybeans, corn, wheat, rye, and other crops. “You also want something growing there when those [crops] are harvested.” 

Dan and his family also raise a lot of cattle where they use the manure produced to put nutrients back in the soil to help build organic matter. He says building organic matter is key because the higher content you have, the more it acts as a sponge to hold available water. 

Another valuable tool they utilize is the planting of a mat of rye alongside their crops. Dan said that it keeps the sun from getting to earth and causing weeds to grow. This method allows them to avoid spraying chemicals on their fields. He believes that chemical usage will be receiving a lot of blowback from government policy in the next five years due to weeds becoming highly resistant to the chemicals used. 

“We are trying to get ahead of the ball game,” Dietz said. 

He says the practices he has adopted prove to be an advantage both environmentally and economically. Dan and his son, Drew, have been invited to speak to students at Iowa State University the past few years, working with the extension to teach students about these exceptional practices. 

Poor management of the earth over the decades has contributed to significant soil erosion and degradation. According to the USDA, Iowa’s rate of erosion is approximately 5 to 7 tons of soil per acre of farmland every year. Finding ways to slow this natural and accelerated occurrence has been a lifelong and strenuous goal of many conservationists. The building of academia and careers revolving around this issue has been due to this need. Using knowledge taught in soil conservation provides a backbone for addressing erosion and other forms of degradation. However, it is vital to use that information to determine what is best for the earth and society. 

How do we, as a society, use soil information? We establish three goals when it comes to planning the soil and land use: 1) Protecting current uses, 2) Promoting new uses, and 3) minimizing conflict between the two. By keeping these goals in mind, we develop compromises to ensure further development without forsaking what works.

For anyone curious about the soil around them, there are fantastic resources that carry information. Web Soil Survey and California Resource Lab are just a couple of available resources for the public to view and use. 

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