Location: Water Management Research
Project Number: 2034-13000-013-002-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Nov 1, 2020
End Date: Jun 30, 2023
Objective:
Determine the effects of whole orchard recycling (WOR) on greenhouse gas (GHG) emissions, soil C and N dynamics, and nitrate leaching.
Approach:
Two almond orchards will be monitored to quantify GHG emissions 2-6 years after whole orchard recycling (WOR) and orchard establishment. One orchard is a commercial field established near Parlier in 2018 (Parlier 2018) and the other is in Kearney Agricultural Research and Education Center (UC KARE) established in 2019. Wood chips were incorporated in both fields at estimated 60-80 tons/ac dry weight. Almond trees were planted following woodchip incorporation. The Parlier 2018 field includes two treatments (woodchip and no woodchip) in four paired treatment blocks. The KARE field uses a split plot design with the main treatments of woodchip or no woodchip plus three nitrogen application rates as sub-treatments in five replications. Emission measurements will be conducted using passive chambers with methods similar to those recommended by the GRACEnet program. CO2, CH4, and N2O emissions will be monitored in both fields bi-weekly (more frequently following fertilization events) for the duration of the project. Nitrate leaching potential will be estimated annually by collecting leachate using resin collectors in subsurface in both fields. The direct change in soil C mass will be measured in 6-month intervals in the KARE field. Change in wood chip mass and subsequent organic C analysis of material will provide an estimate of direct change in C mass in decomposing wood mulch. Cumulative CO2 emissions will be estimated and compared with the direct measurement of C mass. The data will understand the C dynamics affected by WOR and N fertilization rate for developing management strategies.
