Written by Natasha Stewart
Healthy soil is a living system made up of minerals, organic matter, microorganisms, plant roots, water and air. When that system functions well, it supports productive farms, protects surrounding ecosystems and builds resilience in the face of a changing climate.
At Wolfe’s Neck Center, soil is at the heart of everything we do – from regenerative agriculture workforce development and public education programs to farm-based research and farm-to-table dinners. On campus in Freeport, ME, observations and soil testing soil inform all farm management decisions, and support a growing public resource for regional farmers. This article includes information on how we measure soil health, how we’re working to advance practical applications of soil carbon science, and the regenerative practices we use to steward our soils.
Soil Testing and Measurement
On campus at Wolfe’s Neck Center, soil testing plays a key role in guiding decisions about compost application, cover crop selection, nutrient management and long-term field planning (see below for more details on these practices). With 626 acres situated within a delicate coastal ecosystem that includes tidal marshes, estuaries, grassland pasture, forested woodlands and the waters of Casco Bay, understanding what is happening in our soil is essential to protecting both agricultural productivity and the surrounding marine environment.
“As we grow crops and remove them from the soil, whether that’s hay, pasture grasses, fruits or vegetables, we’re also removing the nutrients those plants took up during the season,” said Tom Prohl, Senior Farm Operations Manager. “Without data, even experienced farmers are making educated guesses about what remains in the soil.”
Different crops and weather conditions influence how much carbon, nitrogen, phosphorus, potassium and other compounds remain at the end of the growing season. These are vital nutrients for plant growth, but can be destructive for surrounding ecosystems. Soil testing provides the data needed to manage those nutrients responsibly.
Each spring, our team collects soil samples across campus and sends them to the University of Maine Soil Testing Laboratory where they are analyzed for macro- and micronutrients as well as soil acidity, an important factor in plant health. The results allow the team to apply compost and amendments early in the growing season at rates recommended per square foot. This approach helps ensure crops receive the nutrients they need while avoiding unnecessary inputs.
For a coastal farm like Wolfe’s Neck Center, careful nutrient management is especially important. Excess phosphorus, for example, can move from fields into nearby waterways, contributing to water quality issues in marine ecosystems that support Maine’s coastal economy, including clam and marine worm harvesting.
“Being close to the ocean means we have to be particularly thoughtful,” said Prohl. “If phosphorus levels are already high, adding more would be irresponsible. Soil testing tells us what we need to apply, but just as importantly what we don’t need to apply.”
The data also helps reveal patterns across the farm. Fields closer to manure storage areas may show higher fertility levels, while others farther away may require additional amendments. Because the manure produced by our dairy herd is mixed with carbon-rich sawdust bedding, it provides valuable organic matter but relatively lower nitrogen levels. Understanding those dynamics allows the team to supplement nutrients where necessary and maintain balance across fields.
Beyond guiding annual decisions, soil testing is part of a long term infrastructure strategy. Wolfe’s Neck Center works with partners like Northern Tilth to conduct whole-farm soil assessments as part of a ten-year nutrient management plan. These evaluations look not only at soil health, but also at the infrastructure and systems designed to protect water quality. Manure storage, drainage patterns and filtration systems are reviewed to ensure nutrients are being properly contained and filtered before they can reach nearby waterways.
Together, these layers of monitoring and planning allow us to approach soil stewardship from a whole-farm perspective, using data to support both agricultural productivity and environmental protection.
Applying Soil Carbon Science
Soil testing is not only useful for guiding decisions on individual farms. As we build regional soil testing databases and link results to agricultural and ecological outcomes, soil science can better support decision-making. Wolfe’s Neck Center partners with The Soil Inventory Project (TSIP) on several research initiatives, including the Research Initiative for Northeast Grazing Soils (RINGS). This collaboration brings together university, government, nonprofit researchers and Wolfe’s Neck Center staff to better understand how grazing management influences soil organic carbon across the Northeast.
Soil organic carbon is an important indicator of soil health, helping soils retain water, support plant growth and store carbon over time. Through RINGS, we are working to map existing soil carbon data, develop standardized sampling methods, identify grazing practices that strengthen soil health across the region and provide guidance based on experiences with grazing operations and buyers in the region.
“By comparing their soil health metrics to similar farms within their region, producers can understand where they stand relative to their peers,” says Kris Covey, TSIP Co-Founder and President. “It’s similar to how a smart thermostat or utility bill comparison shows you how your energy use stacks up against your neighbors. Regional benchmarks give farms a meaningful reference point — not just an abstract number, but a relative measure of performance within their specific context.”
These efforts are helping establish regional baselines for soil organic carbon and improving our understanding of how grazing systems can support resilient farms and ecosystems in the Northeast.
Regenerative Practices for Soil Health
Cover Crops
Some of the most important crops are never harvested. Cover crops are planted not for sale, but for the ecological benefits they provide. In the West Bay fruit and vegetable production fields and in our greenhouses at Wolfe’s Neck Center, cover crops protect soil between intensive vegetable rotations.
On a coastal campus like ours, this work is critical. Casco Bay, the Little River salt marsh and nearby tidal flats sit just steps from production fields. Soil that erodes or nutrients that run off do not simply disappear, they move into surrounding marine ecosystems.
Cover crops help interrupt that cycle. Their roots anchor soil during heavy rains and snowy winters. Even after frost kills the plants above ground, their root systems remain in place, holding soil and reducing erosion. Species like oats, peas and buckwheat add organic matter. Legumes help cycle nitrogen. Deep-rooted crops like daikon radish break up compaction, improving water infiltration and soil structure.
Rather than leaving soil bare, we keep living roots in the ground as much of the year as possible. The goal is not simply to grow crops, but to grow soil.
Composting
Composting connects our Organic Dairy and vegetable gardens into a closed-loop system. That means that everything we add to our fields is produced on-campus.
Compost improves soil structure, increases organic matter and enhances the soil’s ability to retain water. On our campus, where heavy marine clay soils can become dense and compacted, these improvements are especially important. A thin layer of finished compost creates a clean, weed-reduced surface that supports consistent crop establishment while lowering the risk of nutrient runoff into nearby wetlands and coastal waters.
The process also reduces waste, fuel use and labor. During the winter months, sawdust bedding mixes with manure in the dairy barn. That material becomes the foundation of our compost, combining carbon from sawdust with nitrogen and phosphorus from manure. Excess barn material is blended with fruit and vegetable waste from gardens and greenhouses. Our DEP-approved composting site allows piles to reach temperatures of 160+ degrees, eliminating harmful pathogens and weed seeds. The finished compost is dry, stable and safe to apply throughout the growing season.
Low-Till and No-Till Practices
Tillage is the mechanical overturning of soil to prepare for planting, manage weeds and improve aeration. In regenerative systems, minimizing disturbance is often a guiding principle. Reducing the frequency and intensity of disturbance lowers fuel use, decreases machinery demands and supports long-term soil health. But it is not a one-size-fits-all solution.
At Wolfe’s Neck Center, we implement both low-till and no-till practices. Because our fields sit near the coast and contain significant marine clay, soils can be dense and slow to warm in the spring. In production fields, we use a low-till approach to alleviate compaction, aerate the soil and help incorporate cover crop residue. Landscape fabric is then applied to reduce erosion, suppress weeds and increase irrigation efficiency.
Inside our greenhouses, we use a no-till system. Each spring, soil is manually aerated with a broad fork rather than mechanically disturbed. This protects soil structure and biology while preparing beds for planting.
Managed Grazing
In our pastures, managed grazing serves as another tool for soil resilience. By carefully controlling when and how long cows graze a field, we give grasses adequate recovery time. This encourages deeper root systems, improves soil biology and increases drought resilience. Manure deposited during grazing returns nutrients to the soil in a natural cycle.
Weekly pasture inventories help our Dairy Grazing Apprentices monitor regrowth, plant diversity and available forage. These observations guide movement decisions, ensuring that grazing strengthens rather than depletes the land. Across fields and pastures, a consistent philosophy emerges. Soil health depends on observation, responsiveness and long-term thinking.
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Across vegetable fields, hay land and pastures, soil testing provides a clearer picture of how the land is functioning and how it is changing over time. When combined with practices like composting, cover cropping, low-till production and managed grazing, that information helps guide decisions that strengthen soil resilience season after season.
By investing in the health of our soil, we strengthen the productivity of our farms, the vitality of our pastures and the protection of the waters that surround us, ensuring that this land can continue to feed our community for generations to come.
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