The Use of Biochar in Agroforestry to Promote Soil Microbial Health, Tree Productivity, and Carbon Sequestration

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Commodities

• Nuts: chestnuts
• Miscellaneous: other

Practices

• Crop Production: agroforestry, biological inoculants, organic fertilizers, tissue analysis
• Education and Training: demonstration, farmer to farmer, focus group, on-farm/ranch research, participatory research, workshop
• Natural Resources/Environment: carbon sequestration
• Production Systems: holistic management, organic agriculture, permaculture
• Soil Management: composting, nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil physics, soil quality/health
• Sustainable Communities: sustainability measures

According to previous scientific studies, biochar’s vast surface area, porosity, and durability provide habitat for beneficial microbes, increase soil water-holding capacity, and enhance soil health and carbon storage (Brewer, et al., 2014; Yao, et al., 2012). Because biochar is fairly easy to produce and can utilize local biomass waste streams, it has the potential of being a widely available renewable resource. It has been studied in annual systems, but rarely in the perennial context of tree crops. Increased interest in regenerative farming and agroforestry to bolster the viability of agriculture in the region and to provide ecological benefits require new data to guide application and usage. Farmers are interested in biochar but have not widely adopted the practice due to a lack of practical knowledge on optimal management. This project will assess the effects of different treatments of biochar, compost, micronutrients, minerals, and microbes on the establishment and growth of a chestnut orchard over a three-year period. 

At the main research site, five treatments will be applied to 120 chestnut trees across three planting rows during the initial planting and on an annual basis thereafter, using locally-produced, lab-tested biochar from sustainably-sourced wood. The study will analyze 60 individual trees divided into 20 experimental units. The research will isolate the effects of straight biochar, straight compost, biochar mixed with compost, and biochar mixed with compost and amended with a mix of micronutrients and microorganisms. We hypothesize that the introduction of organisms and nutrients carried by biochar at establishment, and the subsequent annual treatments of biochar mixed with compost, will have the synergistic effects of increasing soil organic matter, microorganism abundance, plant uptake of nutrients, and the growth and productivity of the subject chestnut trees. Additionally, the use of biochar will return a stable form of carbon to the soil, which we expect will build soil carbon by increasing root growth and soil biota. 

A survey of Northeastern farmers conducted for this proposal showed broad interest in biochar’s potential as a soil amendment, but hesitancy due to a lack of information and data. This study will facilitate farmer engagement by convening a Farmer Working Group of 10 farmers to implement a small-scale trial of the five research treatments on their own farms. Over the duration of this project, farmers will attend two workshops at Arthur’s Point Farm and will collect visual observations on their chestnut trees. This group of farmers will be critical in providing the feedback that will assist in creating a pathway to farmer adoption of this novel approach to regenerative, climate-friendly farming.

Interest in biochar is increasing as a means of enhancing long-term soil fertility and carbon sequestration. A lack of data and farmer experience related to biochar’s benefits and optimal management practices, especially regarding tree crops, is a significant constraint on broader adoption. This project aims to quantify the relationship between inoculated biochar and chestnut trees to provide farmers with a regenerative tool to increase crop vigor and yield. With growing interest in chestnut agroforestry in the Northeast, this project comes at an opportune time for farmers establishing new orchards and for future regional studies with biochar and other tree crops.