Soil Health, Soil Amendments, and Carbon Farming

A farmer holds a handful of healthy soil

Natural and working lands play a vital role in helping California meet its goal of carbon neutrality by 2045. There is huge potential to store carbon in soils on croplands and rangelands in California using soil amendments. In addition to enhancing soil carbon sequestration, soil amendments may provide co-benefits to growers such as increased crop and forage yields and improved soil health.

The Working Lands Innovation Center is testing the carbon sequestration potential of compost, pulverized rock, and biochar amendments and calculating co-benefits to growers. This work contributes to the growing knowledge of carbon farming and provides resources to aid the technical assistance community in advising growers on practical application of soil amendments.

The California Climate Hub has partnered with the Working Lands Innovation Center to create a fact sheet series exploring the relationship between carbon farming, soil health, and soil amendments on California croplands and rangelands. This soil-focused fact sheet series, which is intended for members of the technical assistance community who advise California growers on climate-smart agriculture, provides an overview of carbon farming and addresses the potential benefits of compost, pulverized rock, and biochar as soil amendments. 

 

 

WHAT IS CARBON FARMING?

Carbon farming is the use of specific on-farm practices designed to take carbon out of the air and store it in soils and plant material. Carbon farming practices include application of soil amendments like compost or biochar, conservation tillage, agroforestry, whole orchard recycling, cover crops that maximize living roots, and many others. (See USDA-NRCS Soil Health Management to access the Greenhouse Gas and Carbon Sequestration Ranking Tool for Agriculture). Building soil organic matter on croplands and rangelands sequesters carbon in soils, which helps mitigate the effects of climate change while potentially providing co-benefits for soil health and increased adaptive capacity. Soil amendments may increase the amount of carbon held in soil organic matter, leading to greater carbon sequestration.

WHAT ARE SOIL AMENDMENTS?

Simply speaking, soil amendments are products added to soils to improve soil qualities like soil fertility. Many of the soil amendments that can improve soil health, also sequester carbon. Amendments that increase soil organic matter may improve the water holding capacity and infiltration in soils, which promotes resilience to climate-related impacts such as drought, heat waves, or heavy rains. Additionally, research shows that amendments can promote biological activity and supply vital nutrients, resulting in healthier plants that are less vulnerable to pests and disease.

A schematic showing the difference between soils with and without amendments

 

In this fact sheet series, learn more about carbon farming and soil amendments including compost, biochar, and pulverized rock. Check out the fact sheets through the links below!

Carbon Farming Fact Sheet

Compost Fact Sheet

Pulverized Rock Fact Sheet

Biochar Fact Sheet