Rapid Estimation of Straw Residue Decomposition in Winter Wheat

Project Overview

Project Type: Graduate Student
Funds awarded in 2018: $24,627.00
Projected End Date: 03/31/2019
Grant Recipient: Washington State University
Region: Western
State: Washington
Graduate Student:
Principal Investigator:
Dr. Arron Carter
Washington State University


  • Agronomic: wheat


  • Crop Production: conservation tillage, no-till
  • Soil Management: soil quality/health

    Proposal abstract:

    Less tillage is needed in winter wheat cropping systems in the Pacific Northwest to alleviate soil
    erosion by both winter and water. Wheat straw residue decomposition rate is one way to
    accomplish this. Slow decomposition in the low yielding winter wheat/summer fallow areas will
    leave more residue on the soil surface longer, helping prevent wind erosion. Fast decomposition
    in the high yielding annual cropping areas will limit the need for tillage to help break down
    residue quickly, thereby helping prevent soil erosion by water. This research aims to 1)
    understand the genetic regions controlling rapid residue decomposition, 2) identify a rapid
    method to estimate straw decomposition rate through near-infrared spectroscopy (NIRS), and 3)
    estimate decomposition rates of currently available winter wheat cultivars. A panel of 480
    diverse winter wheat lines grown over two years at five locations will be used to perform a
    genome-wide association study to identify genetic regions controlling residue decomposition.
    These lines will be analyzed for lignin, cellulose, and hemicellulose components, as well as C
    and N ratios. Furthermore, the same straw will be subjected to NIRS, and data will be used to
    develop models to rapidly predict residue decomposition. Finally, released cultivars in the PNW
    will be analyzed to estimate their residue decomposition rates, and information will be provided
    to growers. This information will allow growers to select cultivars specific to their cropping
    system, thereby reducing tillage requirements. Reduced tillage will prevent both wind and water
    soil erosion. The long-term goal of this project is to provide growers with cultivars which are
    specifically adapted to no-till cropping systems, thereby reducing some of the risk associated
    with the transition from conventional to no-till systems.

    Project objectives from proposal:

    1. Phenotype a panel of 480 winter wheat varieties for NDF, ADF, and ADL and C, N, and
    C:N ratio.
    2. Use NIRS and ISIscan software to obtain predictions models for NDF, ADF, ADL, C, N,
    and C:N in winter wheat.
    3. Obtain straw decomposition estimations through the described methods from the varieties
    displayed in the 2018 WSU Extension Cereal Variety Testing Program.
    4. Use the data collected for the decomposition constituents and perform a GWAS to draw
    associations between those traits and known molecular markers.
    5. Create and distribute bulletins containing information about various winter wheat
    cultivars, including the decomposition rates.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.