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Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/10/2014 Publication Date: 10/29/2014 Publication URL: http://handle.nal.usda.gov/10113/60044 Citation: Jabro, J.D., Stevens, W.B., Iversen, W.M., Evans, R.G., Allen, B.L. 2014. Crop water productivity of sugarbeet as affected by tillage. Agronomy Journal. 106(6):2280-2286. Interpretive Summary: A 3-year field study was conducted to evaluate and compare the effect of conventional tillage (CT) and strip tillage (ST) practices on crop water use (CWU) and crop water productivity (CWP) of sugarbeet on a clay loam soil under mid-elevation spray application (MESA) irrigation system in the northern Great Plains (NGP). Seasonal CWU of sugarbeet was not significantly affected by tillage for 2006, 2007, and 2008 growing seasons and CWU averaged across three seasons under CT were almost identical to that under ST. In 2006, root yield and CWP were significantly greater in ST than in CT due to wind storm damage early in the spring which reduced sugarbeet plant population in CT compared with the ST. However, in the ST treatment, the standing stubble protected seedlings from blowing soil under windy conditions. In the 2007 and 2008 growing seasons, sugarbeet root yield and CWP were not affected by tillage. Averaged across three years, root yield was greater for ST than for CT due to a more favorable soil-water-plant environment in the ST. Based on the average of three seasons’ results, the ST system used less irrigation water than the CT system to produce one kg of sugarbeet root yield. The trends for CWP for sucrose yield for the three seasons and their average were similar to CWP for root yield. Based on the average of three seasons, the ST system used less irrigation water than the CT system to produce one kg of sucrose yield. Technical Abstract: Today’s greatest challenge of irrigated agriculture is to produce more food and fiber with less water, which can be accomplished by maximizing crop water productivity (CWP). A 3-year field study was conducted to evaluate and compare the effect of conventional tillage (CT) and strip tillage (ST) practices on crop water use (CWU) and CWP of sugarbeet (Beta vulgaris L.) on clay loam soil under a mid-elevation spray application irrigation system in the northern Great Plains. Seasonal CWU and CWP for sugarbeet root and sucrose yields were determined for the 2006, 2007, and 2008 growing seasons according to the water balance and CWP equations under CT and ST practices. No significant differences due to tillage were found for CWU of sugarbeet for 2006, 2007, and 2008 growing seasons. In 2006, CWP for root yield was significantly greater in ST relative to CT due to wind damage early in the spring which reduced sugarbeet plant population in the CT. The mean value of CWP for root yield across three growing seasons was 10% greater for ST than for CT. Similarly the CWP for sucrose yield for three seasons and their average has similar trends with the CWP for root yield. Based on three seasons results, the ST system used 0.0093 cubic meters (2.5 gallon) and 0.061 cubic meters (16.12 gallon) of irrigation water less than CT system to produce one kilogram of sugarbeet root and one kilogram of sucrose yield, respectively, throughout the growing season. Results also showed that the ST system reaps approximately $0.08/cubic meters of applied water more than the CT system. We concluded that the ST system can be used to produce sugarbeet root yield and CWP comparable to CT or even in some instances greater than the CT system. |