What is the connection between climate change and today’s agricultural practices? Are changing climate patterns affecting your ability, as a farmer, to plant and harvest crops? Farming practices that increase CO2 in the air and create particulate matter, erosion, and field runoff during extreme weather events are contributing to changing weather patterns. The NCBI (National Center for Biotechnology Information) has found “our current agricultural system accounts for approximately a quarter of global greenhouse gas emissions.” It’s not just at the individual farm level but at a global level that agriculture has the opportunity to solve problems.
Which Agricultural Practices Are Contributing to Climate Change?
As a human being on Earth, you first have to recognize that there are more extreme weather events now than in the past. As a farmer, you know your planting dates are earlier (if you can get on your fields), the frost date is later, winter and summer weather patterns are more extreme.
The Arctic polar region is warming, this is causing the “Jet Stream” to move frigid polar air further south into the Mid Atlantic States and warm air to flow into the Arctic. This loop further melts the Arctic polar region.
According to the IPCC (Intergovernmental Panel on Climate Change, AR5), the "summer minimum sea ice extent recorded in 2020 was the second lowest observed since 1979, when satellite observations began."
More open global water means more evaporation and condensation as rain or snow. Global events directly impact your farm and the productivity of your crops.
The change in the flow of the “Jet Stream” has a major impact on the productivity of your farm. In recent years we have had frosts destroy citrus crops in Texas and drought in the Midwest decrease the productivity of corn crops.
How are you contributing to these climate impacts on your farm?
Leaving Soil Bare
If you till in crop residue after harvesting your cash crop you leave the field exposed to both wind and water erosion. According to the NRCS agricultural land with bare soil lost an average of 4.63 tons/acre/year of topsoil. (1) That includes the microorganisms in the soil, the synthetics you applied, and the soil particles themselves. When those soil particles are eroded from your fields they have to go somewhere. At an increasing rate giant spring dust clouds move over the landscape. Those dust clouds warm the earth surface and, because they are abrasive, erode soils they pass over. This creates greater erosion.
Synthetic Soil Amendments
These include the fertilizers, pesticides, and herbicides you use to keep your crop healthy and combat weed competition. But are your crops really healthy?
Without beneficial soil microorganisms your crops are susceptible to disease and prone to greater pest attacks. When you grow monocultures of corn, wheat, or soybeans, or any large area of a single crop you’re factory farming. This way of farming may give you a good yield but is it giving you a good profit?
Adding synthetics to your soil creates an imbalance which allows disease to establish itself in your fields. As you use more synthetics to take care of the problems you are decreasing the organic matter in your soil by killing off beneficial microorganisms. Less organic matter means less water retention and your crops are vulnerable to droughts, which are becoming more frequent with changing weather patterns.
The ability of soil to retain organic matter and soil carbon, necessary to crop health, is diminished every time you till your fields. Tilling sets up the ideal conditions for erosion, pest invasion, and hardpan water issues.
When you till you destroy the microbial balance of your soil. Fungi are especially susceptible to destruction by tillage. Tillage chops up the long hyphae which access water and nutrients for your crops. Without their help, fields are deficient and lack capacity to cycle nutrients and create symbiotic relationships with the plants. To counter these effects, additional inputs are required which can further destabilizes the composition of your soil.
Fungi also create soil macroaggregates. When you hold a handful of soil and it holds together, not like clay but like loam as an aggregate, and you can see white-string-like filaments holding the aggregate together, those are fungal mycelium growing in your soil. These agglomeration of hyphae keep water and nutrients from getting lost on the way to the plant from the surrounding soil.
Soil microorganisms need a great deal of carbon as food and help sequester that carbon in the soil. As larger microorganisms eat smaller ones the carbon remains in the soil and a portion of it is used by plants. The soil food web is disrupted by tilling and the carbon that was stored is released into the atmosphere.
With tilling you also have more water runoff, taking your topsoil and the synthetics you’ve applied into the nearest body of water. This creates algae blooms, affects fish populations, and silts up the water body. A shallower body of water heats up faster and evaporation is greater. Creating more extreme weather events, such as multi day downpours.
But just as farming can cause soil degradation, certain farming practices can mitigate those very problems.
Reversing the Negative Effects of Agriculture on Climate Change
You may think one person can’t have any impact on an issue as large as climate change. In some ways you’re correct, but every solution starts with one action. Your actions will be seen by your neighbors and they will see your success. When they begin to practice regenerative farming practices also the impact will be greater and we will see a mitigation of climate change. Today, only a fraction of farmers use agricultural practices that have a positive impact on the climate. But those farmers are experiencing better crop health, soil fertility, and more profit. Which agricultural practices that have a positive effect on climate change could you implement on your farm first?
When you change from deep tilling to no-till or reduced tilling your soil structure will improve and extreme weather events like floods and drought will have less impact on your farm profits. Aggregated soil holds water for drier periods while it also allows water to percolate in so you don’t have wet, unworkable areas in your fields.
Every field you use no-till on will be a field with a stronger microbial community. The use of no-till with cover crops reduces erosion and decreases the amount of inputs needed for a productive farm, as well as retaining moisture in a "spongy" soil.
When you use no-till agricultural practices with cover crops soil erosion is minimal. Numerous studies have shown that reduced till and cover crops can decrease soil erosion by as much as 87%. (2)
Having your soil covered all year round gives it a coat of armor. When your neighbor’s dust comes across your field it may abrade your cover crops but it won’t take your topsoil with it. Cover crops, used wisely, also increase the nitrogen in your soil and feed the beneficial microbial community that will give you healthier crops with less inputs.
Cover crops are used for many different purposes. If you have clay soil a radish cover crop will put down deep roots and break up the clay for better water infiltration. If your soil is sandy and you want to add organic matter then a rye grass and vetch mix might be your answer.
Cover crops can solve many problems, you need to talk to a crop consultant to get the right mix. Many people give up on cover crops just because they didn’t really know which plant would solve their specific problems. Don’t let that be you.
Rotating crops, including a legume such as soybean or alfalfa which fixes nitrogen, in a 3–4-year rotation of corn, pasture, wheat, soybeans not only increase the amount of nutrients available in the soil but it also creates a diversity of microorganisms. Including pasture in your rotation allows you to incorporate livestock as a secondary revenue stream. Properly managed livestock also create more fertility through their manure and stomping the grass.
Even with no-till, pathogenic soil microorganisms have a tendency to outcompete beneficial microorganisms when only one crop, a monoculture such as corn, is grown on the same acreage for a number of years. The monocrop environment is perfect for host-specialized “domesticated” pathogenic organisms because it differs dramatically from the natural ecosystem which allows a wide variety of microorganisms.
In research conducted by McDonald et al, they concluded that ag ecosystems should be more diverse, both over area and time. They defined this as "dynamic diversity."
"…an over-riding principle is the need to increase agro-ecosystem diversity in a dynamic way that fluctuates regularly…in order to impose disruptive selection on populations of crop pathogens and force them to make trade-offs among traits.”"(3)
Rotating crops decreases the likelihood of pathogenic microorganisms getting the upper hand but combined with no-till it increases the number of beneficial microorganisms. Your crops will have a much better chance of surviving extreme weather events, whether flood or drought.
When did we make the assumption that we had to use synthetic fertilizers and pesticides on our farms? Why did we make that assumption? Is it still a valid assumption?
These are important questions because the use of herbicides, pesticides, and fungicides determine the ability of microorganisms and beneficial insects to live as allies on your farm. The use of a chemical kill down on cover crops is common but those chemicals are usually also antibiotics. Even if you do practice no-till and use cover crops you’ll have a weak soil microbial community because of the kill-down.
Nature is very efficient. If you allow her to supply the microorganisms to feed your crops instead of relying on synthetic fertilizers you will impact climate in multiple ways. Synthetics are highly energy intensive to manufacture or mine. Creating compost on your farm from livestock manure requires little extra expense and a little extra time. Synthetics destroy the microorganisms in your soil whereas organic matter in its numerous forms maintains a robust microbial community. Your entire farm is part of your profit center, not just the fields where you grow cash crops.
Consider Your Entire Farm Part of an Ecosystem
When you drive in your driveway you see more than fields. Youi might see outbuildings, flower borders, vegetable gardens and fruit and nut trees and shrubs. You might also see a chicken coop and livestock in pasture.
The more your farm mimics nature the more beneficial birds and insects you will have as allies. Yes, you may need to buy netting to drape over your berry bushes so you get more berries than the birds. But if they’re not eating your berries, they’re eating bugs.
Regenerative agricultural practices combine the benefits of cover crops, no or reduced till, and crop rotation to build healthy soil with a balanced microbial community. Surrounding your field with native plants brings beneficial insects and retains water. It also adds needed biodiversity for soil health.
It may not be possible, on your farm, to incorporate cattle but chickens are easily added to fields after harvest. They are also beneficial in orchards to remove larvae and worms from fruit that drops from the tree. While your chickens are scavenging for seeds and bugs, they are also fertilizing your field or orchard. The more feedback loops of nutrients in and nutrients out you can create on your farm the more profitable it will be.
What Processes on Your Farm May be Contributing to Climate Change?
When you look at all aspects of your farm as a whole it’s easier to see how you are impacting climate change. It’s not just about your soil. Less use of the tractor by using cover crops and no-till is less diesel exhaust you have emitted as an atmospheric pollutant. If you’re setting a good foundation of healthy soil you’ll have far less stresses on your crops, they’ll be able to use their own natural defense mechanisms against pests and disease. If you’re growing row crops how far do you have to truck them to the grain elevator? That trip is part of your profit, or loss, and your climate impact. Consider both your ROI and climate change when you incorporate regenerative agriculture practices on your farm.
Adapting to Different Agricultural Practices
Farmers have always been adapting to new farming technologies, weather constraints, and market demand. When you adapt your agricultural practices to include cover crops and no-till there will be observable, relatively immediate impacts. You will see the impact of cover crops on soil retention, water absorption, and soil texture. These are benefits that you can continue to improve on.
Farming is a learning curve. There will always be a new weed, a different pest, an unusual weather pattern. These are all aspects of Climate Change and your agricultural practices will determine if extreme weather patterns continue or if you and your neighbors can begin to move climatic events in a direction that improves life for your farm and the world.