Innovative Project Building Healthy Rangeland Soil at Hicks Canyon Ranch

By Karisma Wilson,

December 13, 2023

Last week marked the California Department of Food and Agriculture’s (CDFA) Healthy Soils Week. As ranchers and farmers know, healthy soil is the foundation of viable agriculture and resilient ecosystems. Here in Marin, one ranch, with the support of the CDFA and MALT, is experimenting with using soil amendments traditionally used in orchards and row crops – gypsum and lime – in a rangeland setting.

Why Healthy Soils Matter

As Marin is faced with increasingly unpredictable weather events, like extended droughts and heavy rainfall, soil health management is one of the few defenses land stewards have in the fight against climate change. 

Healthy soil is defined by an increase of organic matter in the soil, infiltrating plant root systems and allowing more water to be retained. When rainfall is stored in the soil, the impacts of drought can be greatly minimized. With increased carbon content and water storage in the soil, stronger and deeper root systems can proliferate. Soil health is directly linked to the overall well-being of the planet, influencing crop productivity, water quality, and carbon sequestration, while replenishing nutrients and filtering our waterways. 

Over time, environmental factors and historic, intensive agricultural practices can degrade soil, emphasizing the need for interventions that enhance its vitality.

Amending Soil with Gypsum and Lime

Soil improvement projects can involve several methods that increase organic matter in soil, such as no-till seeding and cover crops, but innovative practices like incorporating compost, gypsum and lime can improve plant productivity and build soil resiliency. Although gypsum and lime are commonly used in row crop and orchard agriculture, they arerarely applied to rangeland pasture settings because of the scale of implementation. 

Gypsum is a sulfate mineral that adjusts soil structure by counteracting the detrimental effects of soil compaction, promoting better aeration and water infiltration. Gypsum breaks down compacted clay particles, preventing soil crust formation and creating a more porous soil that enhances the stability of soil aggregates, reducing erosion.

Lime neutralizes soil acidity by releasing calcium ions and raising the pH. Proper pH balance ensures optimal nutrient availability, mitigating the risk of nutrient deficiencies. By improving the pH of the soil, biological activity can increase. Marin County’s often shallow and acidic soils can easily limit diversified plant growth, reducing the amount of forage for grazing animals. 

The Hicks Canyon Ranch Project

Hicks Canyon Ranch – a 623-acre property near Tomales protected with a MALT easement since 2014 – sits near Chileno Valley Road and the Marin-Sonoma border. Dense thickets of native California trees and shrubs enfold nearly the entire stretch of Chileno Creek that flows through the ranch, providing habitat to steelhead trout and many bird species. The tributary that runs through the heart of the ranch has been fenced off allowing for lush riparian habitat to flourish, while the hilly rangelands are utilized for Stemple Creek Ranch beef grazing.

At Hicks Canyon Ranch, ranch manager Aaron Lee wanted to improve pasture conditions and build healthy soils by amending the soil with an innovative method.

“Through the MALT SAP program, we applied gypsum and lime to 65 acres of a pasture that was historically overgrazed and tilled for hay production. The goal of the project is to raise the pH of the soil to acceptable levels for plant nutrient uptake and increase soil aggregation to improve water infiltration and retention within the soil. By improving these two soil health factors we hope to see increased forage production and thus increased soil carbon sequestration in the future.”

-Aaron Lee, Hicks Canyon Ranch Manager

Soil amendments are relatively accessible and simple to apply, providing an easy avenue to promote favorable forage and crop production. Earlier this year, Lee coordinated the application of compost with gypsum and lime through a grant with CDFA’s Healthy Soils Program (HSP) and), as a means of revitalizing the soil. 

While the history of compost application on Marin County’s rangelands is abundant and well-documented, the use of strategic,complementary soil amendments like agricultural lime and gypsum can contribute to vibrant ecosystems, increased agricultural productivity, and a more resilient future for our planet. As stewards of the land, it is our responsibility to prioritize and implement practices that promote and preserve the health of our soils. Learn more about SAP and how MALT can support projects like these.