Nutrient Accumulation of Two Beet Varieties As Influenced By Different Nitrogen Regimes.

The form of nitrogen absorbed by plants can affect the uptake and assimilation of other nutrients. A combination of ammonium (NH4⁺) with nitrate (NO3^-) may enhance growth and quality of crops. To determine the optimum ratio of nitrogen forms to improve yield and quality of two beet varieties, a green house experiment was conducted in research green house of the College of Natural Sciences at the University of Massachusetts in 2012. Treatments were arranged in a Randomized Complete Block Design (RCBD) with three replications. Two modern beet varieties (Detroit Dark Red and Merlin) were seeded in 8 inches pots filled with medium. Nitrogen supply included seven levels of ammonium: 0, 6, 12, 25, 50, 75, and 100% modified as Hoagland’s #1 solution. Also two levels of calcium carbonate (CaCO₃) (0 and 10g per pot) were applied to evaluate the effect of buffer in alleviating ammonium toxicity in plants. The results indicated that higher concentrations of NH4⁺ (More than 50%) declined the fresh weight of beets. The pH increase decreased with increasing NH4⁺ concentrations. Also, plants treated with CaCO₃ showed less toxicity to high levels of NH4⁺ (75 and 100%) compared to those not treated with CaCO₃.