Evaluating the Performance of Biochar-amended Orchard Soils Under Projected Climate Change Scenarios

Commodities

• Nuts: almonds

Practices

• Crop Production: application rate management, cover crops, nutrient cycling, organic fertilizers, water management
• Education and Training: demonstration, extension, on-farm/ranch research, workshop
• Energy: byproduct utilization
• Natural Resources/Environment: carbon sequestration
• Soil Management: nutrient mineralization, organic matter, soil analysis, soil quality/health

Climate change has already made agriculture vulnerable to prolonged dry spells which have greatly affected agricultural yields and soil fertility. Nut trees, like almonds, are the most vulnerable to increased temperatures and water-induced stress. A projected increase of 1.5℃ by the mid-2030s would thus reduce rancher quality of life caused by shortened growing seasons and reduced harvests. Considering these risks, California has started a Healthy Soils to determine sustainable soil practices that farmers can adopt to mitigate risks from climate change. Among these practices is using biochar as a soil amendment; biochar has demonstrated the potential to improve soil health through increased water retention and carbon sequestration, among other benefits. Currently, our team is working on an on-farm demonstration site on a working almond orchard in Madera County, CA to explore the effects of two biochar types applied at two application rates on soil health and greenhouse gas dynamics. We propose to expand the scope of our field demonstration by adding research and educational activities that help inform best management practices for biochar use in orchard systems. Specifically, we propose a lab incubation study using growth chambers to measure the effects of biochar, separate and combined with cover crops, on soil properties and plant productivity under elevated temperatures and CO₂ enrichment. We will also develop new educational resources, including an extension publication that will address gaps between public understanding and soil management practices, and multiple workshops, include a field-day, to demonstrate biochar application in almond orchards. Through these research and educational activities, we hope to demonstrate the role of biochar on orchard soil health and resilience to climate change and to generate new knowledge to inform safe and effective practices for biochar use in agricultural ecosystems.

Research Objectives

• Quantify the impact of the addition of two biochar types and two application rates to soil health, carbon dynamics, and greenhouse gas emissions in an almond orchard system
• Determine the separate and combined effects of biochar and cover crops on soil carbon, greenhouse gas emissions, and soil water retention under projected warming

Educational Objectives

• Develop an extension publication for American Farmland Trust’s (AFT) Farmland Information Center that will address gaps between farmer awareness and current available resources for recommendations on biochar application in orchard systems
• Develop and disseminate best management practices for biochar application in almond orchards and share these practices to orchard growers through outreach events