Measuring the Nutrient Accumulation Rates of High-Yielding Potatoes and Sugar Beets

In-season accumulation and partitioning of dry matter, macro- and micro-nutrients by glyphosate-resistant sugar beet (Beta vulgaris L.) varieties in irrigated production systems are not well understood. A study was conducted to evaluate amounts and rates of dry matter, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), sodium (Na), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), and boron (B) accumulated by a high-yielding, glyphosate-resistant sugar beet variety (BTS 21RR25) on an irrigated Portneuf silt loam soil of southern Idaho. Nitrogen, P, and K fertilizers were applied at agronomic rates based on soil test values.

Whole plants were destructively sampled at 16-d intervals from June 9 (germination) to September 30 (full maturity), separated into tops (leaves, petioles, and crowns) and roots, and analyzed for dry matter amounts and nutrient concentrations to estimate amounts and rates of nutrient accumulation. Total mean accumulation at harvest over four replications was 67.5 t/ha (fresh beets), 268 (N), 69 (P), 529 (K), 200 (Na), 122 (Ca), 109 (Mg), 28 (S), 13 (Fe), 1.85 (Mn), 0.64 (Zn), 0.16 (Cu), and 0.68 (B) kg/ha (total dry plant). Distribution among tops and roots and daily rates of accumulation throughout the growing seasons were measured.

Amounts and rates of nutrient accumulation measured in this study provided information on the time of maximum nutrient uptake and total removal of nutrients at different growth stages. The study results can be used to develop pre-plant and in-season nutrient applications guidelines for glyphosate-resistant sugar beet varieties in high-yielding irrigated production systems.