Rapid Evaluation of Winter Wheat Residue Decomposition Potential
CSANR Project 158
Status: No-cost extension granted
Managing crop residue is essential to conservation farming systems that enhance soil quality. Growers, and the seed dealers they work with, regularly request information on residue decomposition of winter wheat cultivars, but none is currently available. The only information is second-hand after growers have experienced the line on a farm scale. There is a need to quickly assess residue decomposition potential of winter wheat cultivars prior to release to provide growers and seed dealers information on those that decompose rapidly for ease of conservation seeding in high rainfall zones, or decompose more slowly to protect soils in conventionally tilled winter wheat-fallow systems. Previous analysis of winter wheat residue has shown that hard and soft cultivars differ significantly in their neutral detergent fiber, acid detergent fiber, acid detergent lignin, carbon (C), nitrogen (N) and C/N (P<0.05), and that many can be categorized as having characteristics for either “rapid” or “slow” residue decomposition. Near infrared spectroscopy (NIRS) shows promise as a method for rapid, precise prediction of residue fiber characteristics; however, further work is needed to develop adequate calibrations to use NIRS for prediction of winter wheat residue fiber and nutrient content and decomposition. We propose an interdisciplinary project that would build on previously conducted research and address priority areas for soil quality (management of crop residue) and crop breeding (varietal selection to reduce organic waste). Two breeding populations of diverse germplasm were planted at Spillman Farm, Pullman, WA in fall, 2015. Residue will be collected at harvest, scanned using NIRS, and validated using traditional forage fiber, carbon and nitrogen analyses with the overall objective of developing a method to rapidly screen residue from breeding populations.