Building Soil Organic Matter for Robust Systems
Inherent in High Mowing’s mission of providing high quality organic seeds is a dedication to building soil health in our production systems. Because our seed is developed in organic conditions with robust soils, the varieties we offer demonstrate characteristics that allow them to thrive in similar organic systems, on farms and in gardens that also recognize the importance of soil building processes.
The most enduring way to improve soil health in any system is through boosting soil organic matter. If care and consideration are taken to maintain soil health, growers on every scale will find improved quality in their plant health, pest and disease resistance, and even flavor in the finished product.
What is Soil Organic Matter?
Organic matter is the component of soil that includes deposits from plants and animals, cells and tissues of soil organisms, and the soil microorganisms responsible for the decomposition of these various residues. Organic matter can be enhanced in crop production fields through cover cropping, manure management, and reduced tillage techniques.
The building blocks of organic matter are wide-ranging and variant: post-harvest plant residues, partially composted animal manures, green manure cover crops, leaves, grass clippings, or other compostable debris can all be used to increase organic matter. Some soil supplements and fertilizers even include ingredients that boost soil microbial activity, a key component of creating accessible nutrients through the decomposition of organic materials. Although these applications can be beneficial, it is important to keep in mind that supplements and fertilizers are not a substitute for true soil organic matter.
If your soils are struggling to support plant growth, your organic matter levels may need some attention. A dedication to acquiring sources of organic material or - if your budget can allow - fully finished, high quality compost will go a long way in improving your system’s overall health. Any of the sources listed in this article can be used broadly to improve soil organic matter; however, it is also critical to assess soil health through testing and analysis to better target and address your soils’ unique needs (see last week’s article on Nutrient Management for Soil Health). The following are some ways to improve soil health and organic matter through creative soil building techniques.
Diverting Local Waste Streams
Unless you have a mixed animal and vegetable operation, it can seem like a burden to attempt to acquire composted manures for adding to your fields – which, incidentally, is why so many conventional farms have defaulted to the quick and easy way of getting fertility: synthesized fertilizers that provide a shot of nutrients at a low cost to the farmer. But a vegetable grower’s need for diverse fertility sources can play into a unique opportunity for local economies and provide more long term health for your organic system.
For instance: you might not own animals that will produce the nitrogen-rich manure your crops crave for growth. But your neighbor down the road owns chickens that produce manure every hour of every day – which builds up quick. You have a need to acquire; your neighbor has a need to remove. Why not partner to help each other out? It’s a win-win: you achieve a boost in fertility while helping your local community divert a potentially harmful waste stream.
Partnerships such as this can manifest in various ways: you might have neighbors with pigs, cows, goats or sheep that can provide manure or partially broken-down bedding materials; a local business owner might have a large volume of food scraps that can be diverted from the municipal waste stream to contribute to your farm’s compost pile; or a fellow farmer might have some moldy hay, straw, or feed that is no longer of use in their operations.
High Mowing participates in this type of mutually beneficial exchange at our home farm in Wolcott, VT. Our fertility program is based on two rotating inputs: composted chicken manure from our neighbor’s pastured chicken operation, and a rotation of perennial green manure cover crops.
Incorporating Green Manures
An efficient way to provide a stream of organic material for your soils annually is to plan for incorporating green manure cover crops into your crop rotation. At High Mowing, we allow our perennial cover crops like winter rye and hairy vetch to grow for two out of the seven years in our crop rotation. This long-term establishment allows the plants’ roots to mature and bulk up beneath the soil surface. The growth that we see above the soil is mirrored in the subsurface that we cannot see, and the buildup of root systems allows for more microbial and soil organism activity, creating structural integrity; each time the crop above ground is clipped or mown, an equal part of the plant sloughs off from the root system below, which adds to soil organic matter. When it is time to plow the cover crops in, all of the material both above ground and below becomes incorporated into the soil, adding a plethora of organic material.
The best way to ensure your cover crops make it into your soils and boost your organic matter is to plan for them. This can include long-term growth plans like High Mowing’s two year timeline, or it can involve in-season incorporation of beneficial and quick-growing annual crops like buckwheat or field peas. A common use of in-season cover crops to add organic matter and reduce erosion is sowing wide pathways, like those required for tomatoes, with a crop that can be easily mown like annual ryegrass.
Did You Know: Poor Man’s Fertilizer
This time of year in our region of the Northeast, we have a little cheat provided by nature that helps boost our soils’ health. The term “poor man’s fertilizer” was originally used by old-time farmers in the region in reference to snow. This partly frozen precipitation contains atmospheric nitrogen, just like rain. But because snow stays on the ground longer than rain, it allows for a slow release of this nitrogen into the soil during springtime melts. As fluctuating temperatures cause the ground to repeatedly freeze and thaw, the minute cracks in the soil also assist with the slow release and absorption process.
However, without structural integrity our soils cannot access the beneficial nutrients from snow cover at all. Hardy cover crops like winter rye and hairy vetch that can withstand Northeast winters help to maintain soil structure and health, ensuring that the beneficial nitrogen applied by snow cover will not run off and become unavailable for future crops. Another reason to be vigilant in your cover crop planting dates; without the structure of cover crop growth on your fields, much of nature’s beneficial nutrient cycles can be lost over the winter months.
To read Modern Farmer’s report on the importance of farmers building soil & feeding soil microbes, click here.
To learn about the nutrient building potential of soil organic matter, read Ohio State University Extension’s report on understanding soil microbes and nutrient recycling: click here.
To research how to assess and improve your soil health, visit Cornell University’s Soil Health Training Manual: click here.