Four Winds Farms Grows Hemp with Biochar Compost Mixture and Favorable Management

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Four Winds Farms Grows Hemp with Biochar Compost Mixture and Favorable Management 

*Note: This article originally published on July 6, 2020, has been updated to share new data on the progress of the project.

You are invited to view: Four Winds Farm website.

Scott Booher’s Four Winds Farm began in April 2020 to amend their soil with compost and biochar to improve soil carbon content (increase organic matter), nutrient availability, structure, and biology. Together with ARTi, 16 cubic yards of DDG biochar was added to the farm soil along with 204 cubic yards of compost (200 cy of Miscanthus Compost and 4 cy of Chicken Litter Compost). DDG biochar is from dried distillers’ grain, a byproduct of the fermentation of corn. The compost and biochar added 24 US tons of organic carbon to the soil (2 tons from biochar and 22 from compost). This increased the organic matter from 2.98% to 6.04% in 3 years. Other positive results were also seen in soil pH and nutrient availability which we will detail.

How many tons of CO2 have been sequestered and how much soil organic matter has increased since the addition of biochar to the soil? 

ARTi is assisting in this ongoing effort with soil analysis, biochar & compost analysis, monitoring, as well as application.

Added biochar has the potential to store 5.60 tons of CO2 in the soil for at least 100 years. Through improved management and with the compost + biochar mixture that we added, more tons can be stored in the soil. So far, in these 3 years, Four Winds Farm’s soil has sequestered more than 90 tons of CO2. Since this was applied to 1.5 acres as per Scott’s requirements, this means that we have sequestered more than 60 tons of CO2/acre. Essentially, the project is about the integration of biochar and compost to improve soil quality, increase soil organic material, and sequester CO2. Additional positive soil benefits were also seen and we will talk about those.

In 3 years we have sequestered more than 90 tons of CO2 and increased organic matter from 2.98% to 6.04%.

Scott, an organic farmer, intended to plant 1.5 acres of hemp cannabis on his farm. Market forecasts have stated the global hemp market will be worth up to USD 14.7 billion by 2026. (link). The first step was the tilling of the soil which took place over a few months. Tilling soil aims to blend organic matter in the soil, break up compacted soil, help control weeds, or loosen up the earth of the planting area.

Scott and ARTi determined that the soil organic carbon level at his farm needed to be increased. Biochar is one natural solution for this issue. Soil carbon helps plants take nutrients from the soil and biochar is an even more effective form of carbon. Biochar, an amendment that lasts for centuries in the soil, can reduce fertilizer use, help crop yields, and function as a carbon sequestration technique. It is organic matter converted into a carbon form that benefits the soil and can help take on climate change. For more information see the following IBI website (link).

Biochar is added to Four Winds Farm’s soil

The next component to be added is compost. Compost is simply organic material that has partially decomposed through a process called composting. Compost offers soils many positive attributes and is used by the smallest garden to the largest farm.  At Four Winds Farm, the compost is being added to the biochar and then incorporated into the soil to help increase the soil’s organic matter.

From the soil analysis both before and after we could see that the initial pH level was quite good at 6.7 which was raised to 7.5 within 3 years. This change was mostly due to the compost since it was highly alkaline at pH (~11).

As stated previously, other positive soil benefits were seen. The available soil nutrient content (NPK) also increased with the addition of biochar + compost. Available Nitrogen increased from 80 to 105 lbs/acre in 3 years. Available Phosphorus increased from 151 to 743 lbs/acre (by a factor x 5 !!). Available Potassium increased from 227 to 451 lbs/acre (by a factor x 2). This can be attributed to the high nutrient content of the compost. For example, in the chicken litter compost, the NPK value was 4-3-4. Also, the high nitrogen content of the type of biochar used (6.4%) influenced the increase of nitrogen in the soil. This higher nutrient availability also influenced the Electrical Conductivity of the soil because more ions from soluble salts became available. Soluble salts include essential plant nutrients such as potassium, calcium, and magnesium.

The ARTi team needed to know the makeup of soil organic matter at Scott’s farm to gauge the results for later. Soil organic matter is a key component of healthy soils, influencing nutrient availability, water retention, soil structure, microbial activity, and overall ecosystem resilience. It was expected that adding compost would increase soil organic matter. However, to get increased soil organic carbon we needed biochar. The intent is to create a significant reservoir of carbon in the soil. By sequestering carbon in the soil, we can help mitigate climate change by reducing the amount of carbon dioxide in the atmosphere. Ultimately, Scott Booher’s goal was to increase the overall levels of organic matter and organic carbon in his hemp field for soil health. This is the reason for the mixture of biochar and compost.  A comparison chart detailing the changes over time can be found below.

As a result of the initial soil analysis, ARTi calculated how much biochar was going to be needed and how much compost there needed to be added as well. As this is a 1.5-acre hemp field, ARTi determined that 16 cubic yards of biochar carbon added to the soil alongside 204 cubic yards of compost would bring the soil organic matter and soil organic carbon up to beneficial levels. We mean benefits in terms of both soil health and carbon sequestration. Scott tilled the soil and ARTi prepared a compost and biochar mix. ARTi brought 16 cubic yards of biochar, mixed it with compost, and spread it into Scott’s acre.

The results of a soil analysis conducted 3 years after application show not only increased benefits in soil organic matter and carbon but also very good stability.

Exchange cations such as K, Mg, and Ca increased after 3 years. As mentioned, the soil nutrients improved as well. The outcomes from this standpoint are presented below:

As stated, the soil organic matter level was quite low to begin with and this is where ARTi could help. The initial organic carbon level was measured at 2.98%. You can see in the picture below the low level of soil organic material. We first thought that we could bring it up to 5%. After 3 years we have brought it up to 6.04% which is a fantastic result.

Four Winds Soil before biochar and compost

ARTi Biochar delivered and ready to be added

Biochar and compost mix added to the field

The hemp seedlings were to be sown in June 2020. According to an ARTi Agronomist, there are three crucial factors to consider during hemp’s germination stage: substrate, nutrient availability, and water quality.

The hemp plants shown here have developed a yellowing in the lower foliage that indicates a deficiency of nitrogen. This deficiency is being addressed by adding a micro-biological tea to the crops two or three times a week.

Scott has used biological tea, chicken pellets, and mulch to address nitrogen deficiency in crops and to promote fungal activity. These additions also reduce soil erosion and moisture evaporation.

Scott Booher sprays the mulch layer with the microbiological tea after all the soil has been prepared.

The improved quality soil achieved after the amendments

Four Winds Hemp seedling begins to sprout

The entire project shows the remarkable potential of working with regenerative agricultural practices. We can all see there are sustainable approaches to farming that address environmental aspects of farming.

Biochar and compost application has been demonstrated to have the potential to sequester more than 80 tons of CO2 in the 1.5-acre field due to greater soil health and increased biomass production, deposition of plant matter, and also due to increased microbial biomass in the soil.

Support Documentation:

Soil Report 2020

Soil Report 2023

Biochar Characterization

 

 

 

 


×These 90 tons of CO2 were calculated as follows

1) First, we figured out how much soil was in the area we treated. We applied biochar+compost to 1.5 acres of soil, with an average density of 87 lb/ft3, at a depth of 6 inches. This gave us a total of 1405 tons of soil.

2) Over three years, the application of biochar+compost increased the soil’s organic matter by 3%, which equates to an increase of 42.15 tons of organic matter (3% x 1405 tons of soil).

3) To convert this organic matter to soil organic carbon, we divided 42.15 tons by 1.72, a factor recommended by USDA NRCS to transform soil organic matter into soil organic carbon. This gave us 25 tons of organic carbon

4) Finally, we converted the 25 tons of organic carbon to CO2 by multiplying it by the conversion factor 44/12. This factor helps us convert the molecular weight of carbon to the molecular weight of elemental carbon dioxide. The result was 92 tonnes of CO2.

×These 5.60 tons of CO2 were calculated following the next steps:

1) We determined the carbon storage value of the biochar using the IBI Classification Tool. This tool takes into account factors like the H:C ratio and the amount of Organic Carbon present. For this instance, the carbon storage value was found to be 508 grams of carbon per kilogram of biochar.

2) Next, we converted this carbon storage value into grams of CO2 per kilogram of biochar by using a conversion factor of 44/12. This factor helps us convert the molecular weight of carbon to the molecular weight of elemental carbon dioxide. After this conversion, we arrived at 1863 grams of CO2 per kilogram of biochar.

3) We then transformed the grams of CO2 per kilogram of biochar into tons of CO2 per ton of biochar, recognizing that 1 ton equals 907.185 kilograms.

4) The value in Step 3 was multiplied by the total tons of biochar applied, considering an average density of 375 lb/cy. Obtaining 5.60 tons of CO2.

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