Sugar beet - nutritional summary

A deficiency of any single nutrient is enough to limit crop yield and the availability of each nutrient needs to be related to the crop requirements. A review of nutrient uptake and offtake reveals which nutrients are required at which growth stages together with the role of each nutrient.

These data show the importance of the early uptake of nitrogen and potassium and the importance that the applied nutrients are available for the sugar beet when required.

Macronutrients

Of the macronutrients nitrogen and potassium are required in the highest quantity for maintaining high yields of sugar beet.

Maximum demand occurs approximately three to four months after sowing. The table below shows that phosphorus (P) and magnesium (Mg) uptake in particular develops very slowly, as the roots of the young beets have only a limited extraction capacity for these nutrients. Application and soil incorporation of water soluble fertilizer P is therefore of special importance. 

Since sugar beet prefers nitrate nitrogen so a proportion of the nitrogen should be given in this form. A subsequent dressing of nitrogen may be applied up to 90 days after sowing. Excessive plant contents of nitrogen and protein adversely affect sugar extraction, therefore the nitrogen supply should drop in the last third of the growing period.

As potential beet yields and thus nutrient removal figures vary between sites and seasons it is appropriate to express nutrient removal on a standard basis.

Micronutrients

Sugar beets are known to require large amounts of micronutrients. Especially boron, manganese, copper and zinc. The table gives average figures of removal of micronutrients in a sugar beet crop.

The significance of fertilization with manganese increases on the stands with neutral and alkaline pH, where the availability of this nutrient from soil decreases. Also, along with the increase of pH, availability of zinc and copper decreases.