Soil health is an essential part of a successful farming operation, but how can we promote productive agriculture in ways that foster soil health, steward the environment and are economically feasible and rewarding? On May 4, 2023, more than 40 people from across Loudoun County met at Potomac Vegetable Farms to discuss methods, programs and tools that promote soil health, which are applicable to commercial growers as well as backyard enthusiasts. Here are a few program highlights:
To kick off the program, Michael Bradford from Potomac Vegetable Farms provided outdoor instruction on composting. Beyond being a medium for chemicals, soil is more complex and “kind of magical”. “We can’t control it, we can only help it,” by creating an environment that fosters “little hot houses” for bacteria and fungi to grow, creating things that promote soil complexity.
How does composting work? Heat is a crucial part of creating great compost. Combining nitrogen rich “green” and carbon-rich “brown” organic matter causes heat to be created, fostering an optimal environment for compost creation. Compost should be between 130-170 degrees for at least two weeks. For PVF, compost is not the main source of organic matter; rather, it’s a helpful soil amendment, it’s “the juice that makes it go”.
Ciara Prencipe of Potomac Vegetable Farms provided a walking tour as she shared her knowledge about cover crops. There is a wide spectrum of benefits to using cover crops, including water retention, increase in organic matter, and reduction in erosion. She discussed seeding techniques and ways to work in organic matter. Ciara also advised that cover crops are great to use after removing landscape fabrics; though landscape fabrics can be powerful tools to suppress weeds, they are not great for promoting soil health since “[soil] is a living thing.”
Additionally, she shared some of her favorite cover crop seed mixes. She recommends including a grain, a legume, and adding a flower for fun. For fall crops, you can use barley, winter peas, and crimson clover. For summer, consider sorghum sedan grass, cowpeas, buckwheat, sun hemp, millet, and sunflowers. Having diversity in your cover crops provides more robust biomass.
Soil and Water Conservation District
Loudoun SWCD’s Urban/Ag Conservationist Chris Van Vlack shared that a guiding goal of Soil and Water Conservation District in this region is to promote the health of the Chesapeake Bay. As such, SWCD can provide funding for projects that meet these goals. Examples of past projects that have received funding include riparian buffering along a stream, nutrient buffering, rainwater harvesting, cover crops, tree planting, and no-till farming. Programs also exist for livestock stream exclusion and water systems to protect water quality and animal health.
Soil and Water Conservation Districts (SWCD) were started as a USDA program created during the dust bowl to prevent farmland from being depleted. In Loudoun County, Loudoun SWCD and Northern VA SWCD support Loudoun County residents by offering resources on best land management practices.
Willie Wood, Executive Director of Northern VA SWCD, asked the question “Why soil test?”
Soil testing helps us maximize yield. Additionally, it also helps us minimize the amount of fertilizer we need to use to effectively produce yields. This has direct implications for the health of Chesapeake Bay when it comes to mitigating the effects of toxic runoff.
Willie encouraged participants to pick up a soil test at VCE Loudoun’s office, 750 Miller Dr. SE, Suite F-3, Leesburg. Additionally, he encouraged people to contact their local SWCD for assistance with crafting their nutrient management plans.
Soil Health in High Tunnels
As the rain started spitting in the afternoon, Extension Specialist Chris Mullins of Virginia State University guided participants through a high tunnel and asked, “What are soil health concerns specific to high tunnels?” Since production is happening beneath the equivalent of a ‘big umbrella’, there is increased protection, but the soil is not getting rain. Snow and wind are the biggest enemies of a high tunnel, and the structure requires support in the center to ensure the work.
We considered organic matter’s impact on the biological aspects of soil, compaction’s physical impact, and total soil fertility. Since the crops grow vigorously, they take up nutrients faster than they would in the field. Additionally, tillage work will impact soil health.
USDA-NRCS Conservation Initiative Programs
District Conservationist Casey Iames shared about USDA-NRCS Conservation Initiative Programs.
Crop Suitability Tool
Commercial Horticulturalist Beth Sastre of VCE Loudoun shared Loudoun County’s recently released Crops Suitability Tool. This online tool combines soil types, aspect (slope orientation), and percentage of slope to determine the best and least suitable sites in which to grow crops in Loudoun County. It lists different types of agricultural soils and their suitability for growing crops like grapes, tree fruits, hops, vegetables, flowers, herbs, small fruits, field crops, pasture, and hay.
To learn how you can promote soil health and use environmentally conscious practices, reach out to VCE Loudoun or Loudoun Soil & Water.
This program was organized by Virginia Cooperative Extension (VCE) - Loudoun, Loudoun Soil and Water Conservation District (SWCD), and Northern Virginia Soil and Water Conservation Districts (SWCD) with the collaboration from Natural Resources and Conservation Services and Virginia State University (VSU), and hosted by Potomac Vegetable Farms in Purcellville, VA.