SODIUM CHLORIDE AND LIME EFFECTS ON SOIL CATIONS AND ELEMENTAL COMPOSITION OF ASPARAGUS FERN

Abstract

Studies have shown the potential for sodium chloride (NaCl) to reduce the incidence or severity of Fusarium root and crown rots in asparagus. With annual applications of NaCl there is concern about possible effects to reduce the availability and uptake of the essential plant elements, especially calcium and magnesium. Studies were established in two commercial asparagus fields in west central Michigan. Soil in both fields is a Spinks loamy fine sand (Sandy, mixed, mesic Psammentic Hapludalfs). In April 1998 NaCl was applied at 0, 560, or 1120 kg/ha with and without the addition of 6.7 Mg/ha pelletized dolomitic lime. Only NaCl treatments were applied again in April of 1999 and 2000. Soil samples were collected from 0 to 15 and 15 to 30 cm prior to NaCl application each year and 5 to 6 months later. Soil samples were collected to 90 cm 31 months after the initial salt application. The top 20-cm of asparagus fern was collected from 12 plants in each plot in August of 1999 and 2000. Soil analyses show the movement of sodium downward over time. Lime application increased the Ca and Mg concentrations in the soil, but had no effect on the elemental composition of asparagus fern. Soil application of NaCl increased the Na concentration in the asparagus fern two to three fold and significantly decreased the Ca and Mg concentrations. The effect of Na on Ca and Mg concentrations in the asparagus were more marked in 2000 than in 1999. This reflects the increasing sodium concentration in the active rooting zone of the asparagus resulting from annual NaCl application.