Effect of Fall and Spring Applied Nitrogen Fertilizer on Growth and Yield of Sugarbeets

The time and amount of nitrogen (N) uptake affects both root and extractable sucrose yield of sugarbeets (Beta Vulgaris L.). Either excessive or late N fertilizer applications and subsequent plant N uptake from applied or residual N sources cause an increasing proportion of the photosynthate to be used for top growth at the expense of both root dry matter and sucrose accumulation (6, 7). Adequate but not excessive amounts of soil and fertilizer N available early in the growing season are needed for adequate top and root growth, while maintaining sufficiently high sucrose percentage and purity for profitable sucrose extraction and yield. For maximum N efficiency and economy, N fertilizer should be applied either near the time of planting or sidedressed early in the season. This reduces the time between N application and N uptake which allows less opportunity for N to be leached out of the root zone, denitrified, or incorporated into soil microorganisms and their by-products. Fall bedding and fertilization of fields to be used for sugarbeets is a common practice throughout the intermountain area of the western United States. Although this practice increases the time between N application and N uptake, it has the following advantages: 1) possible earlier planting, 2) improved moisture level in the seedbed at planting, 3) less irrigation water is required for germination, 4) more even distribution of labor requirement during the fall and spring months, and 5) more even distribution of fertilizer demand. The objective of this study was to evaluate several rates and times (fall and spring) of N fertilizer application as it affects the location of NO3-N within the soil profile, N uptake, seasonal growth rates, dry matter production, sucrose concentration and accumulation, and the partitioning of the photosynthate

Sucrose production as affected by root yield and sucrose concentration of sugarbeets

Refined sugar production of sugarbeets (Beta vulgaris L.) is based on the product of root yield and extractable sucrose concentration. Conditions that affect either of these components may either increase or decrease refined sugar yield. Therefore, it is of prime importance to use practices and conditions that provide adequate top and root growth while maintaining sufficiently high sucrose concentration and purity for profitable sucrose extraction and yield. An inherent inverse relationship exists between sugarbeet root yield and wet root sucrose concentration (9,10,15). Increasing root yields by plant breeding, genetic selection, nitrogen (N) fertilization, agronomic practices, and environmental conditions will generally decrease sucrose concentration (5,14). Milford (13) and Doney (7,8) have both reported an inverse relationship between root cell size and sucrose concentration, and have suggested that the negative correlation results from the opposite effects of cell size on root yield and sucrose concentration. Large cells produce large roots with high root yields and low sucrose concentration; whereas small cells produce small roots with low root yields and high sucrose concentration

Effect of Nitrogen and Irrigation Levels, Location and Year on Sucrose Concentration of Sugarbeets in Southern Idaho

Sucrose concentration of sugarbeets (Beta vulgaris L.) grown in the U.S. varies over a wide range of 10 to 20 percent. Within a climatic zone such as southern Idaho, sucrose concentration varies over a narrower but still wide range of 14 to 20 percent. This variation in sucrose concentration is due to many factors that include variety (19, 24, 26), nitrogen (N) level (18, 23), growth patterns of the crop (3, 16, 25, 29), climatic conditions (1, 22, 28), and other factors that are not fully understood. Refined sucrose production is based on the product of root yield and extractable sucrose concentration. Therefore, it is of prime importance to have practices and conditions that provide adequate root growth while maintaining sufficiently high sucrose percentages and purity for profitable sucrose extraction and yield

Potassium and Sodium Uptake Effects on Sucrose Concentration and Quality of Sugarbeet Roots

Sugarbeet (Beta vulgaris L.) root quality has decreased since the early 1950's in most sugarbeet-growing areas (2). This decrease is generally associated with increased nitrogen (N) fertilizer use which results in decreased sucrose concentration and increased impurities in the roots (13). Decreased root sucrose concentration with N application is generally attributed to the tops becoming the dominant photosynthate sink at the expense of the roots (12). Increased impurities may result from many factors, but are generally associated with higher N uptake that increases the nonsucrose, soluble solids (2, 17). Potassium (K) fertilization of sugarbeets is generally not recommended in the intermountain areas of the western United States because of the general K abundance in the soils and irrigation water (6,8) and the lack of plant response to K fertilizer in numerous unpublished field experiments. Both K, an essential element for plant growth, and sodium (Na), a non-essential element (28), are taken up in large quantities by sugarbeets. The uptake rate and total uptake of these elements depends upon N uptake, plant growth, availability of these elements, year, and genotype grown (1,8,15,17,30)

Potassium and Sodium Uptake by Sugarbeets as Affected by Nitrogen Fertilization Rate, Location, and Year

Fertilization of sugarbeets (Beta vulgaris L.) with potassium (K) is generally not recommended in the intermountain areas of the western United States. This is attributable to the general abundance of available K and sodium (Na) in the soils of this region, irrigation water often containing significant K and Na concentrations (7), and the lack of plant response to K fertilization in numerous unpublished field experiments. Potassium is taken up by sugarbeets in large quantities and is an essential element for plant growth. Sodium also is taken up in large quantities, even in the presence of ample K, but is not considered essential (34). Sodium can substitute for part of the K needs of the plant, and sodium chloride has been used as a K fertilizer substitute in certain humid regions because of its lower cost (21). Positive yield responses have been noted from the addition of Na, even in the presence of ample K (25)

Changes in Nitrate-Nitrogen Concentration in Sugar Beet Petioles as Influenced by Irrigation and Fertilizer Practices

Sugar beets must be properly irrigated and fertilized to maximize sugar production. Both yield and sugar content can be materially altered by water or fertilizer deficiency or excesses (4, 5). Farm operators must carefully manage fertilization and irrigation to obtain the greatest net return from sugar beets

Nitrogen and Phosphorus Fertilization of Sugarbeets

Nitrogen and phosphorus fertilization for sugarbeet production has been practiced in the United States for the past 30 to 40 years. During this period numerous studies have been conducted and summarized (5). Since nitrogen plays a dominant role in the production of high quality roots and maximum sucrose yields, its supply must be accurately controlled. Recent methods developed for predicting N fertilizer needs for sugarbeets in Washington and Colorado (4, 7) are based on the amount of NO?-N in the root zone. However, mineralizable soil N can be a major source of N for plant growth and varies widely in Idaho from one area to another (2, 3). It must be considered if a general procedure for estimating N fertilizer needs is used over a wide area with many soil types and management conditions. Phosphorus is also important in the nutrition of the sugarbeet. Low P levels depress root yields, whereas high levels generally maintain maximum root yields without lowering root quality. Methods have been developed for estimating P fertilizer needs based on the NaHCO?-extractable soil P level (6). Soil test data from England and many U. S. areas suggest that the available soil P levels in many soils are sufficient for maximum root and sucrose production without additional P fertilization. Soil test correlation data establishing P fertilization guidelines for sugarbeets has been limited in Idaho until recently. We conducted 30 field experiments in 1971 and 1972 dealing with N, and two field experiments in 1972 and 1973 dealing with the P fertilization needs of sugarbeets. Since much of this information is published elsewhere, this report summarizes only the soil test results as related to root and sucrose yields

Effect of Fertilizer and Irrigation on Nitrate-Nitrogen and Total Nitrogen in Potato Tubers

This study was conducted to determine the effect of N fertilizer and irrigation management on potato (Solanum tuberosum L.) tuber NO?-N levels and the relationship to the potential health hazard created by high nitrate levels in food products. 'Russet Burbank' potatoes grown using different N fertilizer rates, methods of application, and irrigation levels were analyzed for NO?-N concentration. The NO?-N concentration in the tubers on a wet weight basis varied from 36 to 131, 34 to 75, and 25 to 50 ppm in the 3 years of this study. The NO?-N concentration for each year of study was found to be directly related to the level of applied N fertilizer. The initial concentration and increase in NO?-N due to N fertilizer varied with the season. The addition of manure did not increase the NO?-N level above those to be expected from similar quantities of inorganic sources of N. Phosphorus fertilizer did not increase the NO?-N level. The NO?-N concentration in the tubers where more water was applied at each irrigation was less than on the lower level of applied water at each N rate. These data indicate that greater NO?-N levels in the tubers will result by increasing N fertilization rates. The levels of NO?-N obtained in this study were not expected to contribute substantially to the methemoglobinemia health hazard

Effect of Time and Amount of Nitrogen Uptake on Sugarbeet Growth and Yield

Sugarbeet (Beta vulgaris L.) root quality has been steadily decreasing since the early 1951's with increased use of N fertilizer. Since the extent of these decreases may be associated with the time and amount of N uptake, the objective of this study was to evaluate the effects of several rates and times of N fertilizer applications and N uptake by sugarbeets on seasonal growth rates, sucrose percentage and accumulation, dry matter production, and partitioning of the photosynthate. Sugarbeets were grown under field conditions on a Portneuf silt loam soil (Durixerollic Calciorthids, coarse-silty, mixed, mesic) near Twin Falls, Idaho, in 1977, using four N rates, each applied preplant, mid-June, mid-July, and mid-August. Root yields, sucrose concentration and yield, dry matter production, leaf area index, and plant N uptake were determined from samples taken throughout the season. Adding N fertilizer above that needed for optimum plant growth or delaying N application until midseason caused a greater proportion of the photosynthate to be used for increased top growth at the expense of dry matter and sucrose accumulation in the roots. Sucrose accumulation was maximum from late July until early September; therefore, during this period, addition of N and N uptake by the plant caused the greatest decrease in sucrose accumulation and production at harvest. Increasing N levels decreased sucrose concentrations during the season and at harvest because of 1) increased moisture level of roots, and 2) dry matter produced and accumulated in the roots having a decreased sucrose concentration. The rate of accumulation of stored sucrose was reduced by midseason N application, but stored sucrose was not used for increased growth of beet tops. Excess and late N applications also increased impurities in the beet root, decreasing extractability of stored sucrose, which further decreased refined sucrose production. Early application of N fertilizer at optimum levels should maximize refined sucrose production

Predicting the Nitrogen Needs of Sugar Beets by Petiole Analysis

Sugar beets are grown extensively in areas where fertilization and irrigation can be regulated to maximize sugar production and net returns per unit area. The yield and sugar content of sugar beets can be materially affected by either deficiencies or excesses of water and fertilizer. Nitrogen, in particular, has a great effect on yield and sugar content of beets. Inadequate nitrogen limits root yield. On the other hand, excess residual or applied nitrogen stimulates top growth and reduces root sugar percentage