Application of the EUF procedure in sugar beet cultivation

Summary The relationship between the EUF-nutrient fractions in the soil on the one hand and the nutrient uptake of sugar beet as well as root yield and quality (polarization, α-amino N etc.) on the other is described on the basis of results obtained over several years in surveys conducted in farmers' fields (5000–6000 fields under sugar beet per year) and in field experiments (25–35 sites per year). Statistically significant close correlations with the respective parameters were found for the following EUF nutrient fractions: EUF-NO₃, EUF-P, EUF-K, EUF-Na, EUF-B and EUF-Mn. Within five years it was possible to determine the EUF-nutrient values which are required for the production of 9 t sugar/ha. These EUF values are the following: Ca: 65–70 mg/100 g at 20°C K: 11–15 mg/100 g at 20°C (depending on the clay content) Mg: 3–5 mg/100 g at 20°C Na: 2–3 mg/100 g at 20°C P: 1.4–1.6 mg/100 g at 20°C For calculation of the N fertilizer requirements of sugar beet it is suggested to use the sum of the EUF-extractable N amounts. It was found in Austria, Yugoslavia and Denmark over a period of 3 years that the EUF-N value of 1 mg/100 g soil determined between June and September was equivalent to 40 kg N/ha. If, for example, the analysed soil contains 3 mg EUF-N/100 g, 3×40=120 kg N/ha will be available to the sugar beet crop in the following year.