Having soil organic matter is crucial to a productive farm.
Finding affordable farm acreage is hard to come by for a new farmer. A few years ago, a young farm couple bought the abandoned farm down the road. They knew it had been used for corn, soybeans, and pasture, and when they dug up a shovel of dirt in the field it was just that - dirt.
Their plan was to raise chickens and fiber sheep, sell produce at the farmers’ market, and make some value-added items like knitting yarn, jams, and jellies.
So, they got to work.
They were raising chickens and sheep, so they fenced off parts of the hayfield for the sheep, and when they rotated the sheep to new acreage, they let the chickens in behind the sheep (yes, they lost a few chickens to hawks). Slowly the hayfield became productive as they planted cover crops, let the sheep graze, and the chickens roam.
Today you wouldn’t know it’s the same farm…
Because they got to work creating organic matter in their soil.
Microorganisms break down plant residue and detritus, and in the process release nutrients such as nitrogen, phosphorus, potassium, etc. in plant soluble form.
What Is Organic Matter?
Healthy soil is a combination of water, air, minerals, and organic matter. On average, a typical soil contains 45% mineral, 20-30% water, 20-30% air and 5% organic matter. It seems inconsequential but without that 5% of organic matter there is no soil and plants can’t live sustainably. The microorganisms that convert minerals into plant soluble nutrients are part of the soil organic matter. They, and your crops, need enough water and air to live and thrive.
Microorganisms break down plant residue and detritus, and in the process release nutrients such as nitrogen, phosphorus, potassium, etc. in plant soluble form. Humus, or soil organic matter, is necessary for soil structure, tilth, and cation exchange capacity (CEC). Without organic matter you wouldn’t have crops.
How Does Organic Matter Exist in Your Soil?
Soil is a dynamic entity. The percentages of water, air, minerals, and organic matter is changing every moment. As leaves fall to the ground, they are taken into the soil by arthropods (insects) and microorganisms start the decomposition process. Plants and microorganisms have a mutualistic relationship in which the plant gives off root exudates for the microorganisms and the microorganisms give the plant nutrients in plant soluble form. Microorganisms are constantly busy converting minerals into plant soluble nutrients.
Why Doesn’t Organic Matter Become a Greater Percentage?
It seems logical that as microorganisms continue to decompose organic matter that eventually it would become a larger percentage. But that doesn’t happen mainly because of farming practices. According to the USDA:
Only half the original organic matter remains in most modern cultivated soils. In general, organic matter levels have fallen from 5-6 percent of the soil to less than 3 percent on most cropland soils. Using tillage depletes organic matter. Each time the soil is tilled, oxygen is stirred into it, stimulating microbial action to decompose organic matter at an accelerated rate.
So, we’re playing catch-up just to get that 5% of organic matter in our soils. That 5% is crucial for optimum plant health and high nutrient content in our foods. How to get organic matter into your soil? There are many ways to get organic matter into your soil. You can compost, spread manure, or use organic soil amendments to name a few. One of the easiest ways to keep adding organic matter into your soil is to not till your fields. Most crops grown for profit are not winter hardy, so unless you live someplace like Arizona or Southern California, they will die with the first frost. Leave the stalks or stems in the field, their roots are food for the microbes and will be creating more organic matter during the off-season.
Retain Organic Matter in Your Soil
Change is difficult and, whether you want to admit it or not, it makes a difference what your neighbors think of your farm. Are you plowing and discing your fields? When you do you lose topsoil to wind and water erosion. But even more importantly, you lose microbes that are attached to those soil particles. You lose the “workhorses” of your soil. Without microbes, there aren’t plant soluble nutrients for your plants. You are also exposing the soil organic matter to the air and losing a great deal of it to mineralization.
Here are 5 steps to retain organic matter and increase the profit of your farm:
- Use no-till or strip-tilling on your farm. You will decrease erosion and increase microbial communities. You’ll also save diesel and decrease compaction.
- Plant cover crops and use interseeding. These practices keep growing roots in the soil all year round so the microbes have something to eat.
- Rotate crops and if you’ve been rotating corn and soybeans, add a small grain to the rotation. This one addition increases the complexity of the microbial community and decreases plant and soil pathogens.
- Add perennial forages as cover crops because they develop extensive root systems which add new organic matter to the soil when they die back.
- After harvest, leave the stalks and stems in the field. They will act as food for microorganisms during the off-season.
Diversify Your Farm for Increased Soil Organic Matter
Most farms in North America are either livestock or crop operations. But does there have to be a divide? According to the USDA: Over the last 30 years, 88% of farms have specialized in either crops or livestock. In 2015 8% of farms reported income from just 4 crops. The increase of farms producing ONLY livestock has increased dramatically: Cattle 72%, Dairy 40%, Pork 121%, and Poultry 18%.
The quickest return on your investment in terms of rich organic matter in your soil are compost and manure. Have you considered livestock as a part of your farm or crops with your livestock?
Jeff Goodwin of the Noble Research Institute, Ardmore, Oklahoma, says "this animal-based method of managing to improve soil health is the new frontier for agriculture."
Livestock tramples down vegetation which may be seen as waste, but it’s actually feeding the soil biology. Most farmers feel they have to graze a pasture completely down, but this “waste” is investing in the future, protecting the soil and feeding the soil organisms.
Incorporating livestock in a crop farm will require planning but it’s well worth it. While the livestocks are enriching your organic matter, you’re raising a second revenue stream.
Do You Want to Increase Your Organic Matter and Your Farm Profit?
There are many ways to increase the organic matter in your soil to raise healthier crops. You may want to incorporate livestock, or add biologicals, or plant cover crops. Or all of the above. Fertile soil is created through a coordinated farm plan. Decreased tillage, less use of toxic chemicals and more attention paid to what’s under the soil are all needed to make your farm more profitable.
Remember that young farm couple? They now have a CSA, give lessons on weaving, and grow enough high-quality produce for the farmers market and supply local restaurants. And their jams are really good.
The power of organic matter in the soil!