engleski

Nutritional constraints of sugar beet production in Croatia

In Croatia, sugar beet is the eighth most important but more than 80% of the crop in grown in Eastern Croatia. During 1981-90, the area harvested was 27.850 ha, with a sugar percentage of 15.41%.Due to the war, these values had fallen to 14.200 ha and 14.03 % sugar in 1991-95 (data of Croatian Sugar Beet Producers Association). The decrease in % sugar is explained by climatic changes. The meanmontly air temperature during July and August ranged from 20 to 24oC, some 3 to 5oC above of optimal temperature for sugar beet. Also, in the last few years, fertilizer use has declined tremendously. Total beet root yields are insufficient for the processing capacity (total 19.000 t/day) of the four sugar factories in Croatia. With the aim of improving yields and beet quality, the use of nitrogen (N), phosphorus (P) and potassium (K) fertilizers and other nutritients such as calcium (Ca), magnesium (Mg) and boron (B) should be based on soil testing. For example, in the last three years, 1337 soil samples from 4743 ha were analysed by the EUF method. The percentage of samples with small nutrient contents was 31% for P, 20% for K, 39% for Ca and 17% for Mg. A foliar application of magnesium (as Epsom salt) applied as a 5% solution at 400 l/ha, was tested by applying it twice at an interval of 10 days in June. The sucrose content of the beet was increased, on average by 0.25%, 0.20% and 0.26% in 1995, 1996 and 1997, respectively. A foliar application of Mg was especially effective on soils characterized as having only a moderate supply of magnesium in the soil.

sugar beet; soil nutrition contents; fertilization

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