Using Cover Crops to improve our Soil Health.
Soil health and cover cropping have caught the attention of farmers the world over in recent times and the practice of looking after the land is becoming a common occurrence. And not before time! In the past we focused more on chemical and physical measures to increase soil productivity. New research is showing that the biology of the soil is crucial to health and sustainability and must be restored. The incredible variety and quantity of underground life contributes enormously to how healthy, profitable and sustainable a farm is.
The future of our food supply depends on the health of our soils.
One of the early adopters of cover cropping Gabe Brown from Bismark, North Dakota tells it how it is…...watch this video for a thorough overview.
What is a Cover Crop?
A cover crop is one way to rehabilitate your soil. Cover crops are plantings of annuals consisting of legumes, grasses and broadleaf plants. Anything you can find to fill that seed box really! Cover crops protect the soil while improving it. If a paddock is to lay bare after a cash crop it would be ideal to sow a cover crop to protect the ground. This has a three pronged approach: making it easier for no till, helps with weed control and conserves the soil organisms.
Legumes boost your nitrogen levels as well as many other good things. The daikon radish aerates and breaks up the soil. It also leaves a rotting package in the ground for biology and worms to feed and thrive.
We try new seeds every time in our cover crops. There is no wrong way if you are giving it a go. The “no bare ground policy” is one we like to believe in.
Diversity is the buzz word for soil health and cover cropping. Change it up.
We change our plants each year depending on what we think is needed or what is available or what will actually be able to physically grow in the soil.
It is advisable to mix up the root depth of plants understanding that the deeper the root, the more nutrients available and more root to feed soil organisms. The first year we tried cover cropping on the black flats we planted daikon radish and the root couldn’t penetrate more that a few cms. It was a failure! That was in the same paddock that the video above was filmed in 3 years later. The radish grew to 40cms or more! This paddock isn’t at optimal health yet yet but it’s well on the way.
The more diversity in the plant selection, the more diversity in the soil organisms. The sky is the limit to what you can use. We have seen covers of 13 species. We graze our cover crops and justify this with the added benefit of manure being incorporated into the soil.
It works for us….
The symbiotic relationship between plants and soil biology.
If plants are present there are roots to feed the biology in the soil which in turn feeds the plants. It’s a trading scheme.
Most fungi and bacteria in the soil are beneficial to plants. They make good use of the carbohydrates and nutrients released through the plant roots and trade nutrients like nitrogen or phosphorous back to the plants. While the bacteria and fungi feed on the cover crops they in turn become food for other soil organisms.
If you replace this symbiotic relationship with constant chemical fertilizer the plant then doesn’t look to the soil life for nutrients.
Also if you overgraze or continually farm a paddock the plants may not be capable of supporting a root system that supports the soil life. Changing farming practices in cropping and management of stock should be considered.
If the exchange in nutrients between the plant and the soil organisms isn’t needed there is no point in the symbiotic relationship and the biology dies. The plant will keep looking skywards for you to add the fertilizer. You therefore need to supplement all of the nutrients with topical fertilizers. These tend to increase over time and cost more and more.
The soil biology must be preserved at all costs or be prepared to spend time building it up again. Think of soil biota like your gut bugs. If you don’t have good gut bugs your body will lose it’s ability to fight infections and thrive. The soil is the same.
There is always trading going on between the soil life and the plant.
That amazing little earthworm.
If you are lucky enough to have them, earthworms are usually the most obvious of the many organisms in your soil. There are different types of worms but they do a great job tunneling around creating channels for roots, rainfall and air to circulate about. Cover crops typically lead to bigger numbers of earthworms. This is definitely a good thing.
The development of your soil health and cover cropping can be significantly affected by your management of animals and vegetation. Just be mindful when you eat a paddock right down to the roots. Changing your practices requires a serious commitment to doing the right thing and then not undoing it.
A bit of Trivia.
In a healthy ecosystem more life exists underground than above.
A fistful of healthy soil contains 100 million bacteria; 100,000 protozoa; 10,000 nematodes; Up to 5,000 insects, mites, worms around the plant roots. Now, that’s something worth protecting!
It’s a journey over a few years
We have had failures sure, the soil structure and water holding capacity is what we see improving all the time. We do try and rest the paddocks to reduce overgrazing and decimating the root structure.
Something we regard as very important is – we like the soil to be growing something all the time and for there to be ground cover to preserve the growing population of biology in the soil.
We never thought we would be so excited to open the soil and find a big colony of mycorrhizal fungi 10 years ago. We rate highly any visible signs of life in the soil, the smell, and the feel.
12 reasons why you should consider your soil health and cover cropping.
- Improve your soil moisture retention.- Organic matter acts like a sponge and gradually releases to the plant.
- Weed suppression – provides competition and bare ground encourages unwanted plants.
- Improves the fertility of the Soil.
- Reduces soil erosion – bare soil is easily carried away by wind and water.
- Forage and feed source for animals – our cattle love the cover crops.
- Positive impacts on pollinators – biodiversity encourages beneficial insects and bird life.
- Increases water infiltration and subsoil water quality.
- Helps in the continual fight of disease and pests with increased immunity.
- Protects the soil from heat and cold -damage from evaporation and freezing
- Increased health of animals and crops over time.
- Opportunity produce crop – why not eat the radish or brassica?
- It just feels good to be doing something positive for your land.
Grant Sims is a sixth-generation farmer running the family farm with his wife Naomi and 4 children in Northcentral Victoria Australia. He farms 8500 acres of dryland and some irrigation. The Sims farm has been utilizing no-till since the early 80’s improve the life and function of the soil through biology. Grant has a strong focus on diversity and grows many different crops.
Need another reason to improve your soil health with cover cropping? Have a read of this article – giving incentive to improve soil carbon!