Cover Crops: Key to Healthy Soils
A cover crop is planted after the main crop has been harvested. It grows and enhances the soil, protecting it from erosion over the winter months. Many different species can be used as a cover crop, often several species are planted in a mixture. This short Learn Now video discusses cover crop basics, how they help promote sustainable agriculture, and maintain healthy productive soils.
- [Jeffrey] Hello, my name is Jeff Graybill and I'm an agronomy educator with Penn State Extension in Lancaster County, Pennsylvania.
Today, I'd like to take just a few minutes of your time to discuss cover crops: what they are and how they can be a benefit to farmers, landowners, and to the environment.
Simply put, a cover crop is a crop that protects the soil, which is grown outside of the normal growing season.
Here in Pennsylvania, that's the six-month period from October to April.
It's after harvest, but before next season's planting.
A cover crop can be a grass or a broadleaf and is often a mix of species.
The planting and use of cover crops is considered a soil best management practice or BMP.
Cover crops have many uses and many benefits to the farmer and to the soil.
Farmers will often plant a cover crop to prevent soil erosion.
Here's a photo of a tobacco field after a heavy rain.
Thousands of pounds of soil have washed onto the road.
The lost sediments and nutrients can contribute to poor water quality in local streams and ultimately the Chesapeake Bay.
A cover crop would've protected the soil, preventing this type of erosion.
Farms rely on fertilizer and manure nutrients for high-yielding, nutritious crops.
These often must be applied outside of the growing season when they are not needed.
Cover crops scavenge and hold these nutrients within their roots and leaves, preventing their loss into streams and groundwaters.
When the cover crop is terminated in spring, the nutrients are released to the main crop.
Here in Pennsylvania, cover crops are often harvested.
It's called double-cropping and not only protects the soil over winter, but provides additional forage for the many dairy cows and cattle in the state.
This is a photo of crimson clover being harvested in early-May.
Manure will be applied to the field and corn will be planted by the end of the month.
Protecting soil and water quality and providing extra feed for livestock are traditional benefits of cover crops.
There are, however, many more less-tangible yet important benefits.
Cover crops enhance soil quality and health in many ways.
Living roots will stimulate soil biological and microbial activity.
Soil is a living resource and cover crops feed that resource.
As cover crop roots die and degrade, they add organic matter to the soil.
Organic matter is the engine that drives soil fertility.
It only makes up about 3% of the soil, but significantly improves soil properties.
Here's a photo taken at a local field day.
You can easily imagine how the thick root mass of these species benefits the soil.
Improved soil structure and increased water-holding capacity are two more properties which improve the soil's ability to supply water, helping to carry the crop through periods of drought.
Cover crops increase soil fertility, which often results in higher yields.
Cover crop legume species, such as crimson clover or winter peas, will fix or capture nitrogen from the air and add it to the soil.
Nitrogen is one of the most critical nutrients for crop growth.
Cover crops are excellent at suppressing weeds and can often reduce the need for herbicides.
This is a photo of corn planted into the residue remaining after the cover crop was terminated with a herbicide.
You can see that the soil is well-protected, with little possibility of soil erosion.
When we begin to add up all the benefits and properties of cover crops, it's no wonder that they have the potential to increase the yield and quality of the following crop.
This field of corn was planted without disturbing the soil; it's called no-till farming.
No-till is another technique which protects the soil.
Cover crops are often coupled with no-till farming systems.
Hopefully, you now have a better understanding of what cover crops are and the uses and benefits they can provide to farmers, landowners, and to the environment.
Cover crops are gaining in popularity and are a key component of a sustainable, environmentally-friendly system of modern agriculture.
For more detailed information on cover crops, visit the Penn State Cover Crop website at the link listed here.
Thank you for your time.