Adjustement of fertilizer dressings to achieve high quality and optimum price for potatoes and sugar beet

The quality of agricultural products has recently assumed greater importance. Quality is almost as important as quantity in determining the return to the farmer. Domestic consumers and the processing industry sometimes pay more for high quality especially when quality has an important influence on the efficienty of technological processes. Sugar factories and potato processors will pay more for high quality products. Potato quality is much influenced by nitrogen and potassium fertilizers. The most important criteria are dry matter content and susceptibility to bruising. Quality requirements depend on destination of the potatoes: table, chips, starch manufacture etc. Sugar beet quality determines the cost of sugar extraction. Internal quality can be judged by extractibility index. Good quality beet have high sugar content, low alpha-amino N content, and low potassium and sodium contents. Nitrogen, potassium and sodium fertilizers all influence extractibility. Fertilizer advice should aim to achieve the optimum financial return to the farmer and must therefore take into account effects of fertilizer dressings on quality.