Cover Crops Now Do What Weeds Used To

Sally Krueger

Jan 02, 2019

Believe it or not, weeds actually have a purpose. They were once nature's cover crop.

One of the largest obstacles to overcome in crop production is weed control.

Today, we also have to navigate through herbicide resistance issues with different modes of action, and that means our toolbox of effective herbicides to fight these weeds is shrinking.

Weeds are outsmarting us

The common definitions of a weed include, “A valueless plant growing wild, especially one that grows on cultivated ground to the exclusion or injury of the desired crop.”

Also, “Any undesirable or troublesome plant, especially one that grows profusely where it is not wanted”.

Maybe it is time to understand what the intended purpose of a weed, as it occurs in nature, really is.

Why weeds exist

Like any plant, a weed’s purpose is first and foremost to grow and reproduce.

No one in agriculture would disagree with that—we have all witnessed how prolific certain weed species can be—but weeds are actually nature’s way of protecting and building the soil.

Weeds can often grow faster than our desired crop plants by design.

They contribute carbon to the soil at a rapid pace compared to many cash crops, and weeds have diversity in their structure above and below the soil surface.

Today’s cover crops are designed to do what nature’s weeds used to do

Planted cover crops provide a specific, chosen set of characteristics and benefits to the fields on which they’re planted.

Weeds, AKA “nature’s cover crop,” consists of a multitude of weed species.

There are approximately 250,000 plant species worldwide, but only 3 percent, or around 8,000 species, are considered weeds. For that we can be thankful.

Each weed’s structure exposes the purpose of its existence
  • Weeds that have a taproot can actually help to reduce soil compaction issues.

  • Grasses have thick root masses that can hold soil in place from water and wind damage.

  • The carbon produced by some weeds builds the organic matter of the soil, which helps with water retention, nutrient availability and soil tilth.

  • Weed roots also absorb and move nutrients to a more accessible location to be released when the weed completes its life cycle.

  • Certain weeds can indicate what soil nutrient is deficient by their nutrient uptake.

  • Weeds produce sugars through photosynthesis, some of which are extruded from its roots. These sugars attract and feed the microscopic organisms in the soil to add to soil health.

  • Certain weeds can attract insects to prevent insect damage from desired plants and provide food and habitat for wildlife.

  • Weeds even provide employment in the control of them.

Nature finds a way for each weed species to survive

This is what makes weed control so difficult and frustrating at times.

But it can be helpful to realize that weeds can possess a desirable function to the soil naturally.

Unfortunately, the negative effects of weeds on crops and fields seems to always outweigh the potential benefits.

Thank goodness we have more productive cover crops today, and there are a number of benefits to planting them.

What to do next

Read Three Tips for Cover Crop Success.

ALWAYS READ AND FOLLOW LABEL DIRECTIONS. It is a violation of federal and state/provincial law to use any pesticide product other than in accordance with its label. The distribution, sale and use of an unregistered pesticide is a violation of federal and/or state law and is strictly prohibited. We do not guarantee the accuracy of any information provided on this page or which is provided by us in any form. It is your responsibility to confirm prior to purchase and use that a product is labeled for your specific purposes, including, but not limited to, your target crop or pest and its compatibility with other products in a tank mix. 

Sally Krueger

Jan 02, 2019