Effects of chloride fertilisers on ionic composition and cation-anion balance and ratio of fodder beet (Beta vulgarisL.) grown under field conditions

摘要

Effects of chloride (Cl) fertilisers (NaCl and KCl) on the ionic composition (K+, Ca2+, Mg2+, Na+, NH+4, H2PO-4, SO2-4, Cl-, NO-3), and cation-anion (C-A) balance and ratio of fodder beet (Beta vulgarisL.) were studied under field conditions on two New Zealand soils (Templeton siltloam, Dystic Ustochrept; and Wakanui silt loam, Aquic Eutrochrept). In both soils, at mid season and final harvest, Cl application at 360 kg/ha (590 kg NaCl and 758 kg KCl) increased root K+and Cl-, and Cl-in tops consistently but not K+in tops. The sum of cations (SC) and C-A remained unaffected whereas the sum of anions (SA) increased. With increasing rates of NaCl, root cations were not significantly affected whereas topsand root Cl-increased linearly, indicating that Cl-was easily absorbed and accumulated in both tops and roots of the beet crop. The beet crop maintained constant SC and C-A balance within the range of 0#x2013;1180 kg NaCl/ha applied, but the SA increased linearly with increasing rates of NaCl applied. The ratio (RCA) of SC and SA provided a more consistent and reliable index of yield compared with C-A balance. Beets with low RCA were apparently associated with high fresh and dry root yields and fresh sugar yield.