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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Research Project #438859

Research Project: Influence of Whole Orchard Recycling on GHG Emissions and Soil Health in a Newly Established Almond Orchard

Location: Water Management Research

Project Number: 2034-13000-012-017-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Apr 1, 2020
End Date: Jul 31, 2021

Determine effects of one-time whole orchard recycling (WOR) mulching rate of 60 tons/acre on greenhouse gas nitrous oxide (N2O) and carbon dioxide (CO2) emissions, soil carbon (C) and nitrogen (N) dynamics, and nitrate leaching under surface drip-irrigation system.

A field study will take place at a newly established, commercially owned almond orchard. Trees were excavated in late 2017, ground in tub grinders, spread back across the field, and then disked into the ground the following year. Four half-acre plots were established at random to serve as control plots and did not receive any wood chip mulch. Almond trees were planted following the incorporation of woodchips into soil. Four replicated plots are being monitored. The experimental design is a split plot. The whole orchard recycling and the ‘standard practice’ represent main plot factors. The alleyway and tree row are subplot factors. Trees will be fertilized through a double line drip irrigation system, four times during each year in the first two years of establishment. Greenhouse gas nitrous oxide (N2O) and carbon dioxide (CO2) emissions will be measured for up to three years using chamber methods. Soil carbon (C) and nitrogen (N) will be determined during and after each growing season. Annual nitrate leaching will be measured using resin collector method. Data on emission flux, soil C and N, and nitrate leaching will be analyzed using a mixed model, repeated measures analysis of variance (ANOVA) in SAS.