Published online by Cambridge University Press: 27 March 2009
The effects of applications of sodium chloride (NaCl) and potassium chloride (KCl) ranging from 0 to 720 kg Cl/ha on the yield and uptakes of chloride (Cl) potassium (K) and sodium (Na) by fodder beet were studied in field experiments at two sites in New Zealand. At 360 kg Cl/ha applied, both NaCl (590 kg/ha) and KC1 (758 kg/ha) increased significantly yields of fresh roots, dry roots and fresh sugar content of fodder beet over the minus-Cl plants. Compared with the sulphate anion, chloride application stimulated K uptake in tops and roots. Results indicated that in the beet crop, uptake of K is enhanced with the presence or addition of Cl (as NaCl) compared with SO4 (as NaSO4).
In both soils, total (tops and roots) uptakes of K, Cl, and Na were significantly correlated with fresh roots, dry roots and fresh sugar content. Multiple regression analyses showed that total K uptake was the main nutritional factor which determined yields of fresh and dry roots in the Templeton soil, whilst in the Wakanui soil total Cl uptake and total K+total Cl uptakes determined fresh root and dry root yields, respectively. In both soils, high Cl uptake was required for increased sugar yields.