Location: National Soil Erosion ResearchTitle: Water and temperature stresses impact canola (Brassica napus L.) fatty acid, protein and yield over nitrogen and sulfur Author
|Hammac Ii, Warren|
|Maaz, Tai - Washington State University|
|Koenig, Richard - Washington State University|
|Burke, Ian - Washington State University|
|Pan, William - Washington State University|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2017
Publication Date: 11/7/2017
Citation: Hammac II, W.A., Maaz, T.M., Koenig, R.T., Burke, I.C., Pan, W.L. 2017. Water and temperature stresses impact canola (Brassica napus L.) fatty acid, protein and yield over nitrogen and sulfur. Journal of Agricultural and Food Chemistry. 65:10429-10438.
Interpretive Summary: Adverse weather and depleted soil nutrients have the potential to severely limit crop productivity, but there are questions remaining about their combined effects across different regions. Over the course of six years and two locations in a semi-arid climate, we identified the magnitude and interaction of the effect of weather and soil nutrients on canola grain yield and composition. Soil water, air temperature (weather), nitrogen and sulfur (soil nutrients) were the variables we analyzed. According to the mathematical model we constructed, unsaturated oil, protein and grain yield were highly related to water and temperature variability and much less related to nitrogen and sulfur fertilizer rate. This research tells us that, while we attempt to eliminate the limitation of soil nutrient availability, there are overarching weather variables that can and do severely limit the efficiency of nutrient use and overall crop production.
Technical Abstract: Interactive effects of weather and soil nutrient status often control crop productivity. An experiment was conducted to determine effects of N and S fertilizer rate, soil water, and atmospheric temperature on canola fatty acid (FA), total oil, protein and grain yield. Nitrogen and S were assessed in a 4-yr study with two locations, five N rates and two S rates. Water and temperature were assessed using variability across 12 site-years of dryland canola production. Effects of N and S were inconsistent. Unsaturated FA, oleic acid, grain oil, protein and theoretical maximum grain yield were highly related to water and temperature variability across the site-years. A non-linear model identified water and temperature conditions that enabled production of maximum unsaturated FA content, oleic acid content, total oil, protein and theoretical maximum grain yield. Water and temperature variability played a larger role than soil nutrient status on canola grain constituents and yield.