Storage root quality in sugarbeet in relation to nitrogen uptake

Abstract

SUMMARYThe relationships between the amounts of nitrogen fertilizer applied and taken up by sugarbeet crops and the concentrations of sugar and α-amino-N in the storage root were examined using data obtained from fertilizer-response trials on different soils in the UK and Belgium between 1974 and 1985. On unmanured mineral soils, crop uptakes of N without fertilizer ranged from 65 to 190 kg/ha and increased linearly with the amount of fertilizer N applied. On organic soils or mineral soils that had received large applications of organic manure, crop uptakes of N were very large (295–383 kg/ha) and were not increased by applications of fertilizer N.The amino-N contents of harvested beet increased with crop N uptake. The distributions of crop N to the storage root and of storage-root N to amino-N differed, especially in manured, diseased and drought-affected crops. Greater proportions of crop N were present in the storage roots of manured crops than in conventionally fertilized crops, and more of the storage-root N was present as amino-N in crops affected by virus yellows or drought than in healthy, unstressed crops.The fresh weight concentrations of sugar in the storage root also differed between sites and years but were not consistently reduced by applications of fertilizer N at individual sites. However, when compared across sites, concentrations were negatively correlated with crop N uptakes and the amounts of N in storage roots. This was because particular crops grown on mineral soils with large applications of manure or on organic soils had large N uptakes and exceptionally low concentrations of sugar.The physiological implications of these relationships between N uptake and amino-N and sugar accumulation are discussed.

Impact of Climatic Variables on Carbon Content in Sugar Beet Root

“…This would be in line with the results of Shock et al [62], who found a negative relationship between nitrate concentration in petioles and polarization (albeit only for one of the two years of their study); with Pocock et al [63], who reported that late additions or releases of nitrogen from soil organic matter reduced the sucrose content; and with Draycott and Christenson [64] and Malnou, Jaggard and Sparkes [40], who indicated that an amount of nitrogen above the optimum had a negative effect on sugar yield. Gordo-Ingelmo [17] explained that beet reacts to nitrogen fertilization increases with a greater development of the leaves and roots, which can cause excessive consumption of sucrose and an increase of non-sugars.…”

Effect of N Fertilization Rate on Sugar Yield and Non‐Sugar Impurities of Sugar Beets (Beta vulgaris) Grown Under Mediterranean Conditions

“…Accumulation of harmful N ( α ‐amino N) is also favoured by increased N supply (Winter 1998), a finding confirmed by our results in eight of 12 trials. Amino‐N is the organic form of N which is used by sugar beets for their regrowth (Pocock et al. 1990).…”

“…1990). Uptake of N by sugar beet crop is related to N availability in soil and results in increased α ‐amino N concentrations in roots (Pocock et al. 1990).…”

Root Quality of Sugarbeet

“…The amino N concentration, and often as an accompanying ion, the sodium concentration, increases, so root quality decreases (Fig. 6) (Pocock and Armstrong 1990;Bell et al 1992;Allison et al 1996). As no interaction between variety and N application occurs, varieties with a high concentration of amino N or betaine have a relatively higher concentration irrespective of the N availability and environmental conditions (Hoffmann 2005).…”