Integrating cover crops and organic matter amendments for whole orchard regenerative management

View the project final report

Commodities

• Agronomic: mustard, oats, peas (field, cowpeas)
• Nuts: almonds

Practices

• Crop Production: cover crops, nutrient management
• Education and Training: demonstration, on-farm/ranch research, participatory research, workshop, youth education
• Natural Resources/Environment: biodiversity
• Production Systems: agroecosystems
• Soil Management: organic matter, soil analysis, soil microbiology, soil quality/health

Regenerative agricultural practices in almond orchards include recycling resources, improving soil health, protecting pollinators, improving harvest practices, and minimizing synthetic fertilizer inputs. The complexity of perennial crops requires specific strategies to manage different zones in almond orchards where tree rows are fertigated and irrigated in addition to alleyways which are utilized for growing companion crops or cover crops. Conventional almond orchards typically leave the orchard floor bare and there is a need to use organic matter amendments (OMA) including hulls and shells (HS) as a mulch to protect the soil without compromising profits. Nutshell amendments have been shown to influence soil physical, chemical, and biological properties in almond orchards. Planting cover crops (CC) also has benefits in almond orchards specifically in improving soil quality, nutrient and water preservation, reduced soil erosion risks and weed suppression. Project outcomes addressed soil physical, chemical, and biological properties with HS and CC interactions. Nutrient cycling and decomposition of both practices were analyzed in the first and second years. Field day workshops and demonstrations, articles written on the UCANR Sacramento Valley website, and 4-H college readiness events disseminated information to stakeholders and offered engagement with community members. 

Soil Health Objective: Measured soil physical, chemical, and biological properties under HS OMA. Analyzed short term effects of HS OMA on CC biomass and nutrient status in the soil. Cover crop aboveground biomass sampling measured carbon impacts on the soil and nitrogen uptake that assisted in understanding the relationship between HS OMA and CC. 

Educational Objective: Provided informed data to all stakeholders and members of the industry that include media presentations, conference presentations, and on site field days. Presented research findings at UC Davis and with 4-H high school students interested in studying agricultural science in college. Collected data from grower and farm manager surveys to assess current and potential practices using HS OMA and CC.