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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Research Project #437304

Research Project: Optimizing Fertilization and Irrigation Recommendations in a Newly Planted Almond Orchard after Recycling

Location: Crops Pathology and Genetics Research

Project Number: 2032-22000-017-004-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Nov 1, 2019
End Date: Jun 30, 2022

1. Characterize soil physicochemical properties. 2. Determine microbial carbon and nitrogen usage in wood chip and control soils. 3. Characterize soil biological properties. 4. Characterize the soil moisture retention. 5. Measure tree characteristics. 6. Disseminate data to growers, other stakeholders, and the scientific community.

Overall, the proposed research would test the hypothesis that soil microbes immobilize more nitrogen from fertilization in wood chip plots compared to control. Soil physicochemistry will be assessed via standard methods that measure total and dissolved organic and inorganic carbon and nitrogen pools, pH, moisture, etc. Microbial carbon and nitrogen usage will be determined using methods involving isotope tracers into biomass in laboratory incubations of soil. Soil microbes will be characterized using sequencing of 16S rRNA and ITS genes, PLFA profiling to estimate relative ratio of bacteria and fungi, and fluorometric assays for extracellular enzyme activities (i.e., phosphatase, cellulases, chitinases, etc.). Trees will also be characterized by measuring trunk cross sectional area, leaf tissue nutrient and elemental composition, and stem water potential during the growing season.