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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Research Project #431330

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: 2034-13000-012-11-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Jan 1, 2018
End Date: Dec 31, 2020

Objective:
Determine effects of one-time whole orchard recycling (WOR) mulching rate of 60 tons per acre (T/ac) 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.

Approach:
A field study will take place at a newly established, commercially-owned almond orchard. Trees will be excavated, ground in tub grinders and spread back across the field, then finally, disked into the ground early next year. Four half-acre plots will be established at random to serve as control plots and will not receive any wood chip mulch. Almond trees will be planted following the incorporation of woodchips into soil. Four replicated plots will be monitored. The experimental design is a split plot. The whole orchard recycling and the ‘standard practice’ represent main plot factors. Locations surrounding a tree 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.