Regenerating South Texas Plains with Poultry-Inoculated Biochar

Commodities

• Animals: poultry

Practices

• Energy: biochar
• Soil Management: composting, soil quality/health

Biochar presents a viable solution for remediating depleted soil by increasing soil carbon as well as creating protected space for increased microbiological activity and moisture retention. Its structure has been described as similar to a coral reef for providing protected spaces for life to thrive. A single gram of biochar has approximately 500 square meters of surface area. This large area provides a home for beneficial microbes and fungi, enhancing soil fertility. Biochar attracts and holds moisture, improving the drought tolerance of pasture. Biochar also attracts fertilizers such as phosphorous and nitrogen for later release, and helps prevent its degradation into nitrous oxide, a potent greenhouse gas. Biochar is a permanent soil amendment, with permanent benefits after the ideal biochar to soil ratio has been achieved. One objective of the project is to determine whether distributing biochar, made from recently cleared brush, on selected paddocks will increase organic matter in the soil.

However, initial biochar application has resulted in a decrease in some pasture yields over the first year or two. Most biochar materials are not substitutes for fertilizer, so adding biochar without necessary amounts of nitrogen and other nutrients cannot be expected to provide immediate improvements to crop yields. Instances of decreasing yield due to a high biochar application rate have been reported because biochar has a porous nature that tends to attract and retain the existing biology and moisture that would otherwise be feeding the forage. To mitigate the initial retention issue, inoculating biochar with liquified, mature organic compost (e.g., compost tea) has shown effectiveness. However, it can be burdensome and time-consuming to harvest, age, and store inoculants, and then distribute inoculated biochar throughout the soil. Therefore, our second objective is to determine whether inoculating biochar by having chickens consume it and distribute it on pasture through their manure will add appropriate nitrogen and other nutrients to speed up the increase in organic matter.

This project proposes to take mechanically removed brush stands, render them to biochar, and then introduce the biochar to an experimental group of pasture raised poultry as a feed supplement. Pasture raised poultry practices include housing
birds in floor-less pens that are moved around on grasslands. This provides the birds weather and predation protection while offering direct access to consume forage and distributing the resulting nitrogen-rich manure throughout the pasture. We also anticipate the consumption of biochar will serve to improve the overall bird health and performance but this is ancillary to the improvement of the soil.

The biochar will be derived from woody masses removed from our property to create pasture area suitable for implementation of pasture raised poultry operations. The woody masses are currently piled high throughout the property, are dried and ready to use to create biochar.

There are several methods to producing biochar, each with varying degrees of efficacy. We intend to employ the Cone Pit method, that is to dig a large, inverted-cone-shaped pit about 10 feet deep. The significance of the inverted cone is to control the combustion process by only allowing oxygen to the top layer where the flame is; the area below the flame is oxygen starved but remains hot due to the flame above heating it like an oven. Large, uncut feed stock (woody masses of tree prunings, brush, branches, sticks and other biomass waste) serves as the lower layer and the top layer of wood mass. The use of large feed stock requires less preparation & labor than other methods.

The process begins by starting a small fire in the Cone Pit then introducing feedstock to the top. Additional feedstock is
continually added until the pit is filled just over the top. The fire is monitored closely to ensure an oxygen-free environment below the top. The elimination of oxygen allows for the critical pyrolization process that creates biochar. The heat causes flammable gasses to evolve from the biomass and rise to the top, where they are burned in the flame zone. The fire is maintained and the feedstock is ‘cooked-down’. When there is no more active flame, the process is complete. Then the entire pit is either quenched with water to stop the process or the top of the pit can be covered with dirt, preventing oxygen from entering and allowing it to extinguish itself over time. Once cooled, the resulting mass is crushed to a desirable granular size. The mass can be manually extracted and crushed with tools like shovels or tampers or mechanically with a small wood chipper.

We will follow The International Biochar Initiative’s guidelines for quantity disbursement methods for application. However, there is no published material on using it as a feed supplement. Poultry tend to consume different components of feed at different rates depending on weather, age and other factors. We will introduce the granular biochar to their free choice feed and monitor consumption closely to determine the optimal levels throughout the trials. The birds will consume the mixture and distribute it on pasture through manure, thereby depositing inoculated and moist carbon directly on the soil.

Our project is an on-farm demonstration to test how efficiently and quickly depleted soil can be regenerated and brought
into agricultural production through the use of biochar or inoculated biochar as an amendment.

We will change an important aspect of our current farm operating system to determine the efficacy: introducing inoculated biochar to soil by adding it to current pastured poultry rations. The variable involves both biochar and inoculated biochar. We will make the biochar on-farm using native woody brush material previously removed to re-create native perennial grass pastures. For inoculated biochar, the biochar will be consumed by the animals and deposited to the soil in the animals’ manure.

For this project, we will transfer our current pasture raised meat bird operation to newly-cleared land previously inundated with brush. In total, we will divide our flock into two groups and dedicate up to nine recently-cleared acres for this project:

1. one control plot for rotationally grazed poultry (our current practice);
2. one experimental plot amended with only biochar and no livestock;
3. one experimental plot of rotationally grazed poultry fed free choice biochar that will be distributed as inoculated biochar in their manure.

We will use between one to three acres for each plot, as necessary, to ensure chicken tractors do not travel over the same
pasture area for one year. We will conduct soil testing before the project commences and every six months thereafter. Using best practices, we will take 20 to 30 subsamples from the experimental plots to find a true average. This will account for the wide variability that can occur in soil and forage conditions.

In addition to soil testing, we will make weekly observations, take photos and videos. and capture detailed notes about poultry biochar consumption and what is happening on each plot. We will also monitor the growth of grasses and forbs using the Savory Institute methods (for which Steve has been trained), and track environmental factors such as rainfall and temperature. Ancillary to the project, we will also monitory poultry performance.