Soil nitrate and mineralizable nitrogen are used to predict the root yield potential and N fertilizer needs of sugarbeets. Predicting the required N fertilizer for optimum refined sucrose production based on soil test procedures is needed because inadequate N limits root yield and high levels of N may reduce both extractable sucrose and sucrose yield.Sugarbeets (Beta vulgaris L.) were grown at 14 residual and fertilizer N rates to determine the root yield, sucrose percentage, sucrose yield, and N uptake in relation to the residual, mineralizable, and fertilizer N. A soil test to measure both the mineralizable and NC1,-N level of a soil was found to serve as a valuable guide in recommending N fertilizer for sugarbeets. The amount of N supplied from mineralizable sources in a uniformly cropped and fertilized field is expected to remain reasonably constant if adequate but not excess N fertilizer is supplied each year to the crop grown. Therefore, repeating the test for mineralizable N each year may not be necessary. Determining the amount of N0,-N in the root zone, which is now feasible with rapid and accurate methods of soil analysis, combined with the predetermined mineralizable N, would increase the accuracy of N fertilizer recommendations.
This study was conducted, under several climatic and soil conditions, to determine the effect of N level on sugarbeet yield and quality and to further develop and refine both soil and tissue test methods for predicting N fertilizer needs for efficient refined sucrose production. Previous studies indicate that N fertilizer needs for maximum sucrose production may be predicted by considering yield potential and all N sources. Sugarbeets (Beta vulgaris L.) were grown under field conditions at N fertilizer levels varying from 0 to 448 kg N/ha on six sites throughout southern Idaho to determine root yield, sucrose percentages, sucrose yield, impurity index, and plant N uptake in relation to the residual NO3‐N, mineralizable N, fertilizer N, and petiole NO3‐N. These experiments demonstrated that the N fertilizer needs of sugarbeets can be determined by relating the root yield potential to the measured residual NO3‐N plus a measured or estimated mineralizable N level for an area. Optimum N level from all available soil and fertilizer sources has been found to vary between 5 to 6 kg/metric ton of beet roots produced. Using data from the current experiment and a previous study, N fertilzer could be predicted within 56 kg N/ha of that needed for maximum sucrose yield in 83% of the sites using measured NO3‐N and mineralizable N levels, 67% using measured NO3‐N and average mineralizable N levels, and only 12.5% using recommendations by fieldmen. Linear correlations were found between the total available N, total plant N uptake, other plant N variables, and root quality factors, like percentage sucrose and impurity index. These relationships confirm previous findings and will be useful for predicting root quality, optimum harvest date, and for verifying recommended fertilization practices. The use of the proposed soil and tissue test will improve root quality and sucrose production, as well as production efficiency, that will economically benefit the consumer, producer, and manufacturer.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.