Final report for FNE23-057
Project Information
Pitney Meadows Community Farm (PMCF) was acquired in 2016 by a non-profit organization that guarantees its continued use as a farm with a conservation easement. Our mission is to grow food for the community and involve the public with their soils and food supply through educational and agricultural programming. Approximately 15 acres of the 166 acre property are currently in production. It is the last active farm in the City of Saratoga Springs, N.Y.
We have identified low soil Carbon/Organic Matter levels and low soil biological activity as factors limiting the productivity of our soils. In this study, we used areas not currently in production to conduct additions of compost and cover crops, either minimally or normally tilled in, to determine the most effective way to increase soil Carbon and biological activity in our sandy soils in Haying, Cropping, and Soil Building modalities. We measured soil Carbon and OM levels in the Cropping trial plots before spring planting and after fall harvest to determine the crop depletion of Carbon/OM stores. Results from our research were mixed. While most short-term changes were modest, we documented statistically significant SOC gains in select cropping treatments and established high-quality baselines, methods, and maps that position Pitney Meadows for rigorous, long-term tracking. The practical implications for farms on sandy soils are clear: carbon accumulation is possible, but it is slow, depth-specific, and highly sensitive to consistent inputs and disturbance patterns. Because of the lack of clear data trends, we did not complete our planned outreach.
This project seeks to:
Objective 1) Determine the rate that using cover crops and applying compost (made from the materials available to us) will increase soil Carbon/OM and soil biology in our system of haying, cropping, and soil building. And to determine whether long-term storage capacity is affected by tilling in these materials rather than leaving them at the surface.
Objective 2) Determine the rate at which our current uses of the property (various crops and hay) deplete soil Carbon/OM.
Objective 3) Design a long-term management plan for restoring and then maintaining soil Carbon/OM and biological activity in our farm soil ecosystem, including cropping patterns, resting periods, and soil treatments. This information will be available to other farms to use in developing their practices.
The property that is now PMCF had been in the same family since approximately 1862 prior to our purchase. Obviously our understanding of land use history during that period is limited. For about the last 25 years before the creation of PMCF, the property was leased to third parties who cropped it continuously in a monoculture of corn. We know little about what practices were used during that time. We do know that our soil is very sandy, and we suspect that chemical usage during the corn period may have diminished the soil biological community.
Low crop yields during our early years caused us to test the soils. While levels of most nutrients appear satisfactory or relatively easily remedied, soil organic matter was around 3% (UVMExtension). The Cornell Soil Health Lab rated biologically active Carbon as 44 and soil respiration (microbial activity) as 11, both on a scale of 100 points. Thus we have identified increasing soil Carbon as a priority. Soil Carbon, soil organic matter, and soil biological activity are all critical elements of soil fertility. They affect soil structure, the soil’s ability to hold water, and are responsible for transforming some nutrients into forms usable by crop plants. An interest in increasing soil Carbon/OM is likely to be shared with a large number of farms, especially those with sandy soils and those who wish to convert their operations from highly dependent on chemical fertilizer and pesticide applications to more sustainable and environmentally friendly practices.
We propose to investigate the best methods for increasing soil Carbon/OM by dividing the land not scheduled for crops for the next three years into experimental plots to be treated by planting green manure cover crops and by the addition of compost to the soil surface. We will also use both minimal tilling and normal tilling to see whether incorporation of organic material into the soil has any impact on how well Carbon/OM is maintained and soil biology is impacted. We will test soil Carbon/OM each spring and fall for three years. The results will tell us how much Carbon we can add to our soils per unit of time and the most effective way of doing that. Soil biology will be tested for baseline levels in the first spring of the trial (2023) and in autumn of 2023 and thru the length of the trial.
In addition, we will measure soil Carbon/OM in experimental plots scheduled for cropping each spring before planting and each fall after harvest. Tests will be done for the standard crop rotation that we use for food crops as well as for hay production. This information will tell us how quickly we are depleting soil Carbon/OM.
By combining all of this information, we will be able to make informed decisions about how much acreage can be cropped, how much recovery time is needed after cropping, and what are the best management practices during those fallow periods. The end result will be to design a system for both this farm and others on similar (glacial sand) soils that increases and then maintains high soil Carbon/OM, reduces the need for artificial inputs that could pose environmental risks, improves a farm’s productivity, and potentially increases net income and reduces costs depending on how well the no-till treatments perform.
We farm on just over 11 acres with a market garden for our CSA members and larger production fields for other programs, including our Farm to Pantry, Food as Medicine, and Farm Stand programs.
At Pitney Meadows Community Farm, we embrace a holistic approach to farming, recognizing the farm as an ecosystem with interconnected elements. Our core focus revolves around soil health, as we acknowledge its pivotal role in sustaining healthy plants, animals, and ultimately, the well-being of our community. Our foundational agricultural practices are as follows:
Remineralization:
This process involves balancing mineral nutrients within the soil. Conducting annual soil tests enables us to analyze mineral content and subsequently apply necessary minerals through natural amendments such as limestone, elemental sulfur, and rock dusts. This practice fosters improved soil structure, creating an optimal environment for microbiological activity, essential for rendering minerals accessible to plants.
Cover Cropping:
Employing cover cropping, or green manuring, entails sowing specific plant mixes to enhance soil quality. These plants facilitate carbon and nitrogen sequestration, root-based compaction layer disruption, and nutrient accumulation from deeper soil levels. Incorporating these crops enhances organic matter and augments biological activity within the soil. Our current green manure mix includes, but is not limited to: sorghum sudan, millet, buckwheat, sunflower, cowpea, triticale, and cereal rye.
Minimal Tillage:
Recognizing the potential adverse effects of tillage on soil structure, carbon oxidation, and microbial populations, we strive to minimize our tillage requirements. Our approach involves a semi-permanent raised bed system, practicing thoughtful crop rotation, and consistently supplementing nutrients through compost and organic matter.
Microbiology:
Microbiology constitutes the living component crucial to soil health. Serving as effective recyclers, soil microorganisms convert plant and animal residues into elemental forms that support new life. Our agricultural practices prioritize the promotion of soil biota populations and diversity.
Organic Practices:
While not formally certified as organic, our farm strictly adheres to organic practices. All amendments and fertilizers originate from natural sources, and we produce our compost on-site. Natural pesticides are sparingly applied only when deemed necessary. We have also strategically established permanent and seasonal plantings to provide habitat for beneficial insect predators.
Ecosystem Stewardship
In acknowledging the farm as a natural ecosystem, we have collaborated with the Natural Resources Conservation Service (NRCS) to plant trees along a traditional riparian corridor spanning 4 acres. This extensive planting, comprising over 1500 trees, aims to provide a windbreak for our cropping areas, create wildlife habitat, build soil health over time, and restore a riparian environment. Additionally, we are actively transitioning an additional 4 acres into permanent native pollinator species plantings.
Cooperators
- - Technical Advisor
- (Researcher)
Research
Study Site
This study was conducted at Pitney Meadows Community Farm in Saratoga Springs, NY (43.07°N, 73.80°W), a 166-acre farm with 15 acres dedicated to vegetable production. The region is characterized by a Dfa climate zone (hot-summer humid continental climate) with four distinct seasons, cold winters, and hot summers. The primary soil classifications at the site are Windsor loamy sand and Deerfield loamy fine sand (USDA-NRCS Web Soil Survey). The farm has a history of intensive monocropping and soil erosion, which have contributed to poor soil health conditions. In collaboration with The Soil Inventory Project and the USDA Sustainable Agriculture Research and Education (SARE) program, Pitney Meadows has been implementing experimental trial blocks since 2023 to evaluate the impact of conservation agriculture practices on soil health metrics, including soil organic carbon and organic matter, through the addition of compost, cover cropping, and reduced tillage management.
Experimental Design
The experimental site consists of 20 treatment plots managed under different tillage and amendment combinations with two replicate plots per treatment combination. The plots are organized into three management systems:
- cropping plots (minimum tillage and conventional full tillage, each with and without compost addition),
- soil building plots (minimal tillage and no-tillage practices, each with and without compost addition), and
- hay production plots (with and without compost addition).
Since 2022, each cropping trial block has been managed with a three-year summer crop rotation and winter green manure amendments. In 2024, all cropping blocks were dedicated to potato production.
Soil Sampling
Soil samples were collected at all plots in summer 2023 and summer 2024, with an additional sampling of cropping plots only in summer 2025. At each sampling location, soil samples were collected at two depth intervals: 0-15 cm and 15-30 cm. Within each plot, samples were collected at five locations, with two depth samples per location.
Soil collection was conducted using The Soil Inventory Project (TSIP) auger-drill system (Jensen et al 2024), consisting of a 1” auger and 13 × 15.1 × 7.5 cm (9-gauge) aluminum collection box fused to a 30 × 9 cm rotating base. Using a handheld drill, the auger draws soil from below the box into the collection compartment. All soil samples were sent to Ward Laboratory (Kearney, NE) for analysis of total carbon percentage by dry combustion.
Spatial Interpolation and Change Analysis
Soil carbon measurements collected at field sampling points were spatially interpolated to create continuous surface maps using inverse distance weighting (IDW) interpolation. For each unique combination of soil depth, treatment, and year, raster surfaces were generated using IDW interpolation with a maximum of 10 neighboring points and an inverse distance power parameter of 0.5.
Temporal changes in soil carbon were quantified by calculating delta rasters, which represent the difference between the latest and earliest sampling years for each depth-treatment combination. These change maps were computed by subtracting the earliest year raster from the latest year raster, with resampling applied where necessary to ensure grid alignment.
Statistical Analysis
Results were visualized using boxplots showing total carbon percentage by year, faceted by treatment group and soil depth. Plots were created for three experimental areas: cropping plots (minimal till and full till with and without compost), soil building plots (minimal till and no till with and without compost), and hay plots (with and without compost), at both 0-15 cm and 15-30 cm depth intervals.
Prior to statistical analysis, outliers in total carbon measurements above 2 standard deviations from the mean were identified and removed. Data distribution was assessed using histograms and quantile-quantile plots.
To assess temporal changes in soil carbon within each treatment group, one-way analysis of variance (ANOVA) was performed with year as the factor. Post-hoc pairwise comparisons between years (2023-2024, 2024-2025, and 2023-2025) were conducted using Tukey's Honest Significant Difference (HSD) test, with adjusted p-values to control for multiple comparisons. These analyses were performed separately for each treatment combination.
All spatial analyses were conducted in R version 4.5.1 (R Core Team) using the following packages: sf for spatial data handling, sp for spatial point operations, raster for raster processing, gstat for geostatistical interpolation, dplyr for data manipulation, and tidyr for data transformation. Statistical analyses were performed using base R functions. Data visualization was conducted using ggplot2. Final map layouts were prepared using ArcGIS Pro (Esri).
Results and Discussion
Soil carbon at 0-15 cm increased from 2023 to 2025 in plots in the cropping plots with full tillage without compost (difference = 0.448%, p = 0.0446, Fig. 1). We also observed an increase in the median carbon concentration at 0-15 cm from 2023 to 2025 in plots with full tillage with compost additions (Fig. 1); however, this increase was not statistically significant. At 15-30 cm, cropping plots with full tillage with compost showed a significant increase in soil carbon from 2024 to 2025 (difference = 0.626%, p = 0.0355, Fig. 2).
In the soil building plots, soil carbon at 0-15 cm was similar in 2023 and 2023 across treatment groups. In contrast, soil carbon decreased from 2023 to 2024 at 15-30 cm for plots with no till and compost additions and plots with minimal till and compost additions (difference = 0.389%, p = 0.0461 and difference = -0.60%, p = 0.0067, respectively, Fig. 10). All other treatment combinations showed no significant temporal changes in soil carbon across the study period, with adjusted p-values exceeding 0.05 for all pairwise comparisons.
Soil carbon accumulation is a slow process that typically requires many years to decades to detect meaningful changes. The lack of significant differences in most treatment groups may be due to the relatively short duration of this three-year study period. Continued long-term monitoring will be necessary to fully assess the impacts of these management practices on soil carbon sequestration.
Soil texture also influences carbon stabilization. The sandy soils at Pitney Meadows may require extended monitoring periods following amendment to detect meaningful increases in soil carbon. Sandy soils have inherently limited capacity to stabilize soil organic carbon due to reduced mineral surface area for organo-mineral associations (Hassink, 1997). This can result in faster turnover rates and lower equilibrium soil carbon concentrations (Müller & Höper, 2004). Consequently, sandy soils not only store less carbon but also may require substantially higher organic matter inputs to maintain functional SOC levels compared to clay-rich soils operating under similar climatic and management conditions.
While we report soil carbon as concentration (%), translating management effects on soil carbon require quantifying carbon stocks (Mg C ha⁻¹) using concurrent measurements of bulk density. Management practices have the potential to alter soil structure and bulk density, which may confound concentration-based assessments of soil carbon. Future analyses incorporating bulk density measurements—ideally using an equivalent soil mass framework to account for temporal changes in soil density—would allow us to quantify soil carbon stocks to further understand management effects on soil carbon sequestration at Pitney Meadows Community Farm. Future research should also prioritize longitudinal studies that examine how repeated management practices—such as tillage and compost application—influence year-over-year carbon stocks, and whether consistent inputs result in increased carbon stocks over time. Equally critical is the need to quantify carbon emissions from under different management regimes to better understand the net carbon balance of these systems.
Fig. 1. Comparison of soil carbon concentration at 0-15 cm from 2023 to 2025 across management practices in cropping plots including: minimal till, minimal till + compost addition, full till, and full till + compost addition.
Fig. 2. Comparison of soil carbon concentration at 15-30 cm from 2023 to 2025 across management practices in cropping plots including: minimal till, minimal till + compost addition, full till, and full till + compost addition.
Fig. 3. Spatially interpolated change in soil carbon concentration at 0-15 cm from 2023 to 2025 in cropping fields under different management practices.
Fig. 4. Spatially interpolated change in soil carbon concentration at 15-30 cm from 2023 to 2025 in cropping fields under different management practices.
Fig. 5. Comparison of soil carbon concentration at 0-15 cm from 2023 to 2024 in hay plots with and without compost additions.
Fig. 6. Comparison of soil carbon concentration at 15-30 cm from 2023 to 2024 in hay plots with and without compost additions.
Fig. 7. Spatially interpolated change in soil carbon concentration at 0-15 cm from 2023 to 2024 in hay fields with and without compost additions.
Fig. 8. Spatially interpolated change in soil carbon concentration at 15-30 cm from 2023 to 2024 in hay fields with and without compost additions.
Fig. 9. Comparison of soil carbon concentration at 0-15 cm from 2023 to 2024 across management practices in soil building plots with different management practices including: no till, no till + compost, minimal till, and minimal till + compost.
Fig. 10. Comparison of soil carbon concentration at 0-15 cm from 2023 to 2024 across management practices in soil building plots with different management practices including: no till, no till + compost, minimal till, and minimal till + compost.
Fig. 11. Spatially interpolated change in soil carbon concentration at 0-15 cm from 2023 to 2024 in soil building fields with different management practices including: no till, no till + compost, minimal till, and minimal till + compost.
Fig. 12. Spatially interpolated change in soil carbon concentration at 15-30 cm from 2023 to 2024 in soil building fields with different management practices including: no till, no till + compost, minimal till, and minimal till + compost.
References
Hassink, J. (1997). The capacity of soils to preserve organic C and N by their association with clay and silt particles. Plant and soil, 191(1), 77-87.
Jensen, K. H., Faehndrich, C. S., Colzani, E., McClure, M. L., & Covey, K. (2024). Rapid soil harvesting using a novel soil auger system for farm‐scale soil carbon estimates. Soil Science Society of America Journal, 88(1), 192-202.
Müller, T., & Höper, H. (2004). Soil organic matter turnover as a function of the soil clay content: consequences for model applications. Soil Biology and Biochemistry, 36(6), 877-888.
This SARE project advanced our understanding of carbon behavior on glacial sand soils under real-world farm constraints. While most short-term changes were modest, we documented statistically significant SOC gains in select cropping treatments and established high-quality baselines, methods, and maps that position Pitney Meadows for rigorous, long-term tracking. The practical implications for farms on sandy soils are clear: carbon accumulation is possible, but it is slow, depth-specific, and highly sensitive to consistent inputs and disturbance patterns.
As a community farm embedded in an urban setting, we are committed to sharing findings with growers, educators, and policymakers, and to hosting applied research that strengthens soil health in the Northeast. We welcome proposals from academic and community research partners interested in agricultural soils, forest edges, riparian corridors, and farm-scale regenerative practices. Together, we can turn this three-year pilot into a decade-long evidence base that improves management on sandy soils and contributes measurable climate benefits for the region.
Education & outreach activities and participation summary
Participation summary:
We had originally planned various outreach activities, including posting signs about the trials, hosting yearly on-farm meetings, presenting findings at NOFA NY, and creating a one-page handout. The lack of significant results made much of this activity moot. We do, however, plan to link this report to our website, share it out through our email marketing and social media channels, as well as use the report to solicit other research studies on our land.
Learning Outcomes
We learned valuable lessons through this grant specific to being a community farm. Using our land for academic and agricultural resource is a priority in our strategic plan. We did, however, learn that there are signigicant capacity issues with managing the rigor of a study like this in balance with our own farm programming and administrative capacity. Scientifically, we learned:
- Cropping plots with full tillage with compost showed a significant increase in soil carbon from 2024 to 2025
- All other treatment combinations showed no significant temporal changes in soil carbon across the study period, with adjusted p-values exceeding 0.05 for all pairwise comparisons.
- The sandy soils at Pitney Meadows may require extended monitoring periods following amendment to detect meaningful increases in soil carbon.
- Future analyses incorporating bulk density measurements—ideally using an equivalent soil mass framework to account for temporal changes in soil density—would allow us to quantify soil carbon stocks to further understand management effects on soil carbon sequestration at Pitney Meadows Community Farm. Future research should also prioritize longitudinal studies that examine how repeated management practices—such as tillage and compost application—influence year-over-year carbon stocks, and whether consistent inputs result in increased carbon stocks over time. Equally critical is the need to quantify carbon emissions from under different management regimes to better understand the net carbon balance of these systems.
Project Outcomes
n/a
There were limitations in time scale plus some soil dynamic variables that couldn't be factored in, and given that the results are sort of opposite of what we loosely/broadly understand about tillage, compost, and carbon, it seems like there is more to the story here that the study couldn't quite capture. If we want to continue being partners to deep and valuable agronomic study, our best bet is to find a way to commit to long-term consistent practice & data collection.