Fertilization Recommendation for Sugar Beet Farming

It is well known that fertilization is important for the success of producing agricultural products. It is self evident that harvesting removes nutrients that are contained in the crops harvested, which again have to be re- placed by fertilization. Excessive fertilization renders ample harvests, but on the other hand wastes money by using to much fertilizer and pollutes the environment.

However there is one crop, that also shows reduced production results by over ferti- lization: the sugar beet. This is due to the two years growth cycle of the sugar beet.
In the first year the plant grows from seed to form the beet, which has the function of collecting and storing nutrients for the second year. In this second year the plant sprouts from the beet to form the full grown plant, blooms and produces seeds again.

In order to find optimum conditions, energy and minerals are stored within the beet: energy in form of beet sugar, minerals e.g. nitrogen in form of amino acids.

During sugar production beets are cut up into small chips which then are extracted with hot water. Beet sugar is a di-saccharide consisting of two hydrocarbon rings: one glucose and one fructose ring. The acid (amino acid) present in the extraction liquid increases hydrolysis of the di-saccharide into the two mono saccharides which afterwards do not cristallize into white sugar but remain in solution to increase the amount of mo- lasses.

In other words: Too much nitrogen in the soil is stored by the beets in form of amino acids which in turn lead to decreased white sugar yield and increased molasses pro- duction. By the way: sugar beet is the only agricultural product that actually shows re- duced yields caused by over fertilization. Sugar factories get less white sugar and cannot improve yield, as the reason for that is raw material inherent. Therefore we reach multiple advantages by optimizing fertili- zation: we avoid wasting money, we protect the environment and we avoid production losses. This also is the reason, why fertili- zation recommendation lab are usually operated by the sugar factories.

Wich are the main optimization parameters?

The most important main nutrients are nitro- gen (in form of nitrate and ammonia), phos- phor and potassium (NPK).
Nitrate, ammonia and phosphor are deter- mined by wet chemistry, potassium by flame photometry. A basic analyzer therefore would be a four channel automatic analyzer. In order to get information about calcium mobilization, the pH value is measured.

How are nutrients extracted from the soil samples?

There are various ways to extract the nu- trients from the soil sample. If simple means should be chosen, doing a CAL (Calcium- Acetate-Lactate) extraction that will provide phosphor and potassium and a CaCl2 extract providing the nitrogen fractions and the pH value are recommended. The extraction pro- cess is achievied by placing a quantity of dried soil into a plastic bottle containing the extraction liquid, placing it onto an overhead shaker and letting the mixture extract for one or two hours. Then the suspension is filtered.

Which steps are necessary for the analysis?
  • Soil sampling in the field.
  • Drying the samples in a drying oven.
  • Aliquote the sample for the analysis.
  • Extraction in two diferent extractionliquids to mixture.
  • Filtration of the suspensionsto get clear liquids.
  • Autoanalyzer determines phosphate, nitrate and ammonium by color reactionsand potassium by flame photometry.
  • Calculation of recommended use of fertilizer for sugar beet production.
  • Written information for the farmers for individual fertilization of his fields.
Which experience we have?

Our partner LaborChemie has a 40 year ex- perience in optimizing white sugar yield in Austria and Germany. We can supplies both, the equipment performing soil analysis and the technological know how to operate the laboratory and perform the recommendation calculation.