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ARS Home » Pacific West Area » Pendleton, Oregon » Columbia Plateau Conservation Research Center » Research » Publications at this Location » Publication #174263
Title: ON-COMBINE SENSING AND MAPPING OF WHEAT PROTEIN CONCENTRATION

Author
item Long, Daniel
item ENGEL, R - MONTANA STATE UNIVERSITY
item CARPENTER, F - INSTRUMENT DISTRIBUTORS I

Submitted to: Crop Management at www.cropmanagement.org
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2005
Publication Date: 5/27/2005
Citation: Long, D.S., Engel, R.E., Carpenter, F.M. 2005. On-combine sensing and mapping of wheat protein concentration. Crop Management [on-line]. Available: http://www.plantmanagementnetwork.org/cm/element/cmsum2.asp?id=4841.

Interpretive Summary: Wheat protein levels that vary within farm fields are a potentially useful source of information for precision agriculture. This study investigated a new sensor designed to operate on a combine harvester for mapping grain protein levels within farm fields. The sensor measured protein concentration to within 0.66% during harvest of a 45-ac wheat field. In addition, the map of grain protein derived from the sensor appeared highly similar to the map derived from test samples in the same field. The results are sufficiently promising to suggest that on-combine spectroscopic sensing of grain protein concentration based on near infrared transmittance is technically feasible. Grain protein maps produced in this manner can be combined with grain yield maps to compute variable-rate N recommendations and estimate straw yield for soil conservation and fertilization programs.

Technical Abstract: Site-specific measurements of grain protein concentration, in addition to grain yield, are potentially useful for assessing spatial variability in cereal crop production as needed in precision agriculture. This study investigated an on-combine spectroscopic sensor for mapping grain protein levels within farm fields. The optical sensor was calibrated in the laboratory to test samples of hard red spring wheat (r^2=0.99, SEP=0.08%). Grain protein data for spring wheat were then acquired for a 45-ac dryland wheat field, and compared with test samples that had been manually sampled from the combine's exit auger. Ability of the sensor to predict protein values declined in the field (r^2=0.55, SEP=0.66%). However, a map of grain protein concentration derived from on-combine sensing was highly correlated with a test map of grain protein (r=0.93). The results are sufficiently promising to suggest that on-combine spectroscopic sensing of grain protein concentration based on near infrared transmittance is technically feasible. Grain protein maps produced in this manner can be combined with grain yield maps to compute variable-rate N recommendations and estimate straw yield for soil conservation and fertilization programs.