Effect of nitrogen supply by soil depth on sugarbeet production and quality

Authors: Tarkalson, David; OLSEN, DAVEY - Amalgamated Sugar Company; King, Bradley - Brad

Submitted to: Journal of Sugar Beet Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2022
Publication Date: 12/7/2022
Citation: Tarkalson, D.D., Olsen, D., King, B.A. 2022. Effect of nitrogen supply by soil depth on sugarbeet production and quality. Journal of Sugar Beet Research. 59(1-4):7-22. https://doi.org/10.5274/jsbr.59.1.7.
DOI: https://doi.org/10.5274/jsbr.59.1.7

Interpretive Summary: Nitrogen supply is important in sugarbeet production to optimize yield and quality. Determining the effect of N supply by soil depth on sugarbeet production in the Northwest U.S. is important to continue fine-tuning management practices while minimizing negative environmental impacts. To accomplish this objective, a greenhouse column study was conducted by Amalgamated Sugar Company and USDA-ARS Northwest Irrigation and Soils Research Laboratory. The study was conducted using thirty columns filled with 0.9 meters of soil. The treatments consisted of adding N fertilizer at a rate of 132 kg N/ha to three 0.3 meter soil depths in the columns (depth 1 = 0-0.3 meters, depth 2 = 0.3-0.6 meters, and depth 3 = 0.6-0.9 meters). Although all treatments (except the control) had a total N supply of 222 kg N/ha in the entire 0.9 meter soil depth, the distribution of the N in the soil profile affected the measured factors. Sugarbeet tuber mass, tuber sucrose mass, leaf (includes stems) mass, tuber N mass, leaf N mass were higher for treatments where N fertilizer was added to depths 1 and 2 compared to when N fertilizer was added to depth 3. Data indicates that sugarbeets were not able to utilize N from depth 3 as efficiently as from depth 1 and depth 2. The N use efficiency measurements (N recovery efficiency, N removal efficiency, and fertilizer N uptake efficiency) were greatest when 132 kg fertilizer N/ha was supplied in depths 1 and 2 compared to when some or all the 132 kg fertilizer N/ha supply was in depth 3. Sugarbeet quality was the same for all treatments. The sugarbeet plants did not utilize N in depth 3 as effectively as depths 1 and 2, and N levels in depth 3 did not negatively affect quality. The findings of this study highlight the need to question the value of a depth 3 soil sample for determining N fertilizer requirements.The cost/benefit evaluation of taking a soil sample to include depth 3 (0.6 to 0.9 meters) needs to be further evaluated in the field.

Technical Abstract: Nitrogen (N) supply is important in sugarbeet production to optimize yield and quality. Determining the effect of N supply by soil depth on sugarbeet production in the Northwest U.S. is important to continue fine-tuning management practices while minimizing negative environmental impacts. To accomplish this objective, a greenhouse column study was conducted by Amalgamated Sugar Company and USDA-ARS Northwest Irrigation and Soils Research Laboratory. The study was conducted using thirty, one meter by 0.3 meter columns filled with 0.9 meters of soil. The treatments consisted of adding N fertilizer at a rate of 132 kg N/ha to three 0.3 meter soil depths (depth 1 = 0-0.3 meters, depth 2 = 0.3-0.6 meters, and depth 3 = 0.6-0.9 meters). Each treatment was replicated six times in a randomized block design. Although all treatments (except the control) had a total N supply of 222 kg N/ha in the entire 0.9 meter soil depth, the distribution of the N in the soil profile affected the measured factors. Sugarbeet tuber mass, tuber sucrose mass, leaf (includes stems) mass, tuber N mass, leaf N mass were higher for treatments where N fertilizer was added to depths 1 and 2 compared to when N fertilizer was added to depth 3. Data indicates that sugarbeets were not able to utilize N from depth 3 as efficiently as from depth 1 and depth 2. The N use efficiency measurements (N recovery efficiency, N removal efficiency, and fertilizer N uptake efficiency) were greatest when 132 kg fertilizer N/ha was supplied in depths 1 and 2 compared to when some or all the 132 kg fertilizer N/ha supply was in depth 3. There were no treatment effects on sugarbeet quality factors. The sugarbeet plants did not utilize N in depth 3 as effectively as depths 1 and 2, and N levels in depth 3 did not negatively affect quality. The findings of this study highlight the need to question the value of a depth 3 soil sample for determining N fertilizer requirements. The cost/benefit evaluation of taking a soil sample to include depth 3 (0.6 to 0.9 meters) needs to be further evaluated in the field.