Carbon Sequestration in Glacial Sand Soils in Haying, Cropping, and Soil Building Practices

Progress report for FNE23-057

Project Type: Farmer
Funds awarded in 2023: $27,843.00
Projected End Date: 02/28/2026
Grant Recipient: Pitney Meadows Community Farm
Region: Northeast
State: New York
Project Leader:
Ian Magnus
Pitney Meadows Community Farm
Expand All

Project Information

Project Objectives:

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.

Introduction:

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.

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Dr. Kristopher Covey - Technical Advisor

Research

Materials and methods:

Methods as proposed

Objective 1 (Measuring Carbon addition): We will establish two study areas of approximately 1.7 acres each in a location that is not currently being cropped. Each area will be divided into 5 treatment plots as follows:

 

1) Haying: managed as a conventional hay crop, cut once per year and removed. 

2) Cropping - Conventional Till: a 3-year summer crop rotation with normal tilling by tractor.

3) Cropping - Minimal Till: a 3-year summer crop rotation with minimal tillage. 

4) Soil Building - Conventional Till: soil-building with minimal tillage by tractor.

5) Soil Building - NoTill: soil-building with no tilling. 

 

One study area (one plot of each treatment listed above for a total of 5 treatment plots) will be supplemented with green manure cover crops, winter only (winter rye, barley, vetch, pea mix) for Cropping plots and both winter and summer (sudan grass, buckwheat, cowpea mix) for Soil-Building plots.  The second study area (one plot of each treatment listed above for a total of 5 treatment plots) will be supplemented with those same cover crops plus the addition of compost: Haying plots, after cutting hay; in Cropping plots both before and after cropping, in Soil Building plots, in conjunction with autumn green manure planting.

 

Carbon/OM addition will be measured by sampling the Carbon/OM content of the soil in all treatment plots. Samples will be collected and analyzed in both spring and fall. A minimum of 5 soil samples at each of two depths (10 samples total) will be taken in each treatment plot, points to be chosen at regular intervals by use of a grid overlaid on the area. Sampling methodology will be described at the end of this section.

 

For all plots, Carbon/OM addition will be measured by comparing spring and fall soil samples.

 

For all plots, soil biology will be measured in the spring of 2023 and then each fall beginning in 2023.

 

Objective 2 (Measuring Carbon/OM, soil biology depletion): For the Haying and Cropping treatment plots, Carbon/OM depletion will be measured by comparing spring and fall soil samples. Soil biology will be measured by comparing yearly fall tests.

 

Objective 3 (Developing a management plan): Once we know how rapidly we can build soil Carbon/OM through addition methods and how rapidly it is depleted by cropping and/or tillage, we will be able to calculate how much fallow time the soil needs between crops and therefore what proportion of our fields can be cropped each year. Biological information will be collected to determine whether increased Carbon and SOM result in automatic increases in biological activity or whether separate inoculation is required.

 

Statistical analysis: Standard parametric statistics such as t-tests and Analyses of Variance will be applied as appropriate to determine differences between treatments (Or non-parametric equivalents if it appears that parametric assumptions are not met.) We will use a method called Empirical Bayesian Kriging to interpolate carbon values. This uses geostatistical methods to estimate carbon values in areas not directly sampled using the known values from sampling to create a full coverage map of carbon values across a larger area.. 

 

Total Carbon/OM sampling will follow the methodology of The Soil Inventory Project (TSIP).  Field researchers sample soil by drilling an auger to 30 cm below the soil surface. Two samples will be taken from each sampling location (0-15 cm; 15-30 cm). The sampling kit comes with two augers, each with a welded collar stop at depth. Field researchers navigate to a sampling location following a map on their phone. Samplers place the metal box with foot plate on the approximate sampling location and press it flush to the soil. Samplers connect augers to a handheld drill. They drill to the pre-defined depth. Soil is poured into a QR-coded bag and the code is scanned into the TSIP sampling app. Sampling takes approximately one minute per sample location.

 

Biological activity and soil organic matter sampling will utilize the same equipment as for soil Carbon sampling. Samples will be taken in each trial plot at the same points as soil Carbon samples. Biology samples will be taken at the 0-15cm depth, bagged and sent to Ward Laboratories for a DNA test.

 

2023 progress

Between the time that we applied for this grant and its acceptance, our Executive Director resigned and the Board of Directors experienced a significant change in membership. These events led to both a delay in funding and questions as to the direction of the organization and commitment to this project. I am happy to report that the Board of Directors has found its footing and a new Executive Director has taken the helm. The result has been a renewed commitment to this project with allocated funding for 2024.

However the 2023 delays in funding approval and support affected our ability to perform as much as desired on this project. Additionally, we experienced unprecedented deer pressure in all of our crop areas. This had a devastating impact on the cropping plots, resulting in no yields at all. As with all farming operations of this type, there were lessons to be learned and we have made adjustments for next year which are detailed below. There were notable results in the soil building blocks. Assessments of the cover crop stands and coverage are also detailed below.

Due to the mixed results of the year due largely to organizational issues, we will be submitting expenses only for the blocks devoted to soil building. We expect a much better result next year in all areas with the adjustments detailed below.

SITE & PROJECT OVERVIEW

There are 5 blocks in this trial: 1 Hay Production, 2 & 3 Vegetable Cropping (tillage & minimal tillage), 4 & 5 Soil Building (Cover Cropping with tillage & no tillage).

Within each block there are 4 plots each with a difference soil amendment: 1 - Compost only, 2 - Compost + Biochar, 3 - No Compost + Biochar, 4 - No Compost or Biochar (ref: FIELD MAP)

Blocks and plots were laid out in early May 2022 and soil sampling performed immediately after. Soil samples were taken at the rate of 5 samples per plot per TSIP sampling protocols which are 1 core to the depth of 0-15 cm and a second core to the depth of 15-30 cm. A single set of samples were taken in May and not sent for processing until later in the year due to funding concerns. Soil samples were not taken in the autumn for the same concerns.

Biochar was added after sampling at the rate of approximately 2 tons per acre. This was applied with a Hopper Spreader

Compost was added to Haying and Soil Building blocks in late August prior to sowing to winter cover crop. Compost consisted of aged horse manure applied with a Manure Spreader at the rate of approximately 16 cubic yards per plot.

Cover Crop sowing dates, species mix and application rates are noted in the sections below. All blocks were initially sown in October 2022 with Cereal Rye at the Application Rate of 40# per acre. This was sown with a John Deere Drill Seeder and sown into existing pasture without any preparation.

 

BLOCK REPORTS

HAYING (H)

The Haying block was oversown in March 2023 with a mix of Red Clover, Timothy, and Annual Rye. This mix was sown with the John Deere drill at the rate of 8# per acre. The block was not cut for hay but was mown in July to 1’  and residue left in place. An application of compost was applied in late August. All plots in the block appear healthy and display the best living mass soil coverage of any block.

 

CROPPING (CT, CMT)

Field preparation on the Tillage block (CT) commenced in late May with the block being mown, disced and finally harrowed. Plastic Mulch was applied in early June.

Bed preparation on the Minimal Tillage (CMT) block was performed in early June. A modified single row minimal till cultivator was used. 

Cropping plan on both blocks was 5 beds in each block; 3 beds of winter squash in a single planting and 2 beds of snap beans in 2 successions. All squash and the first succession of beans were planted after plastic mulch application in June. Winter Squash beds in the Minimal Tillage block were covered with composted leaf mulch applied with the manure spreader.

Initially these plantings fared well with plenty of rain and no need for irrigation over the course of the season. Weeding in the Tillage block became an issue as we had only marginal success with a spider wheel cultivator and the single experienced tractor operator was often engaged in other cropping work. Maintenance of the Minimal Tillage block was much easier in that it only required mowing in the strips between the beds. However, the situation became much more difficult once the deer discovered this planting. Grazing became so severe that the second planting of beans was not performed. There was no yield from any of these plantings.

 

SOIL BUILDING (SBT, SBNT)

Preparation of the Tillage block (SBT) was performed in early June consisting of mowing and discing followed by finishing with a 10’ Perfecta. No preparation was performed on the No-Till block (SBNT). Both blocks were sown at the same time (early June) with a no-till drill (SSWCD) for a consistency of application. The summer seed mix and application rate was: Sunflower, Cowpea, Buckwheat (grain box @ 15#/acre) and Sorghum/Sudan, Millet (seed box @ 6#/acre).

This mix was mown in late August with the Tillage block being disced in. The winter seed mix was sown with the no-till drill as per the summer mix. The winter mix consisted of: Cereal Rye, Winter Pea (grain box @ 56#/acre) and Hairy Vetch, Radish and Mustard (seed box @ 9#/acre).

There was a noticeable difference between the two blocks in both the height and quality of the cover crop with the Tillage block exhibiting better growth and coverage. However there was an equal difference in the two blocks in soil surface coverage after the remains of the summer cover crop was terminated after the first frost. The soil coverage in the No-Till block is nearly total while the Tillage block exhibits 30-50% bare ground.

 

2024 ADJUSTMENTS

With this project now supported and funded, soil samples will be taken in both Spring and Autumn and processed promptly. Several adjustments have been made in response to the experiences encountered this year and are noted in the block plans as follows:

HAYING (H)

This block exhibits good growth and soil coverage. This year the block will be cut for hay when we are cutting other fields for straw (late June - mid July). We expect this to be baled in small square bales and counted. Compost will be applied to the compost plots after cutting.

 

CROPPING (CT, CMT)

These blocks will see the biggest change in practice due to the experiences of the past year. The crop plan has changed due to the deer issues. Both blocks will be planted to potatoes (5 beds per block) in Spring. This will be followed by garlic in Autumn. We have a successful system for these crops in this rotation which consists of a composted mulch application followed by tillage incorporation, rough bed forming which leaves a planting furrow, planting followed by a compost application and initial hilling. Cultivation is performed with 2 passes of a hiller and a single hand/hoe weeding on the hill tops. Harvesting is performed with a Bed Lifter. This will be the practice on the Tillage block (CT).

For the Minimal Tillage block (CMT), we are purchasing a single row no till ripper. Preparation will consist of a composted mulch application followed by the no till ripper, potatoes will be set on the surface followed by a compost application and initial hilling. Cultivation is performed with 2 passes of a hiller and a single hand/hoe weeding on the hill tops. Harvesting will be performed with a Middle Buster.

We have had very little deer browse occur on previous potato crops but are prepared with additional electric fencing to install should this become an issue.

SOIL BUILDING (SBT, SBNT)

We will continue the practices on these blocks per 2023. 

Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.