A project page from the Coastal San Luis Resource Conservation District (CSLRCD) describing a CDFA Healthy Soils Program Demonstration trial launched in 2020 at Cal Poly’s Chorro Creek Ranch. The project, conducted in partnership with Cal Poly State University, is a replicated field trial testing four combinations of compost application and tillage intensity (conventional vs. reduced) on dryland hay production in a cropley clay soil. Monitored variables include bulk density, soil organic carbon, plant-available nutrients, soil aggregation, mineralizable carbon, soil hardness, moisture, and infiltration rates. Preliminary findings show reduced tillage can decrease tractor passes without affecting yield, and that short-term impacts of both practices on soil properties were minimal — likely masked by the site’s already-high baseline organic matter.
