In 1981, in the 8th year of a long-term NPK fertilisation experiment set up on calcareous loamy chernozem soil, the effect of different nutrient supply levels and their combinations were examined on the yield components and element uptake of sugar beet. The soil of the growing site contained satisfactory supplies of Mn, Mg and Cu, moderate supplies of N and K and poor supplies of P and Zn. The experiment consisted of 4N × 4P × 4K = 64 treatments, on a total of 128 plots. The main results can be summarised as follows: 1. Compared to the control extreme supplies of NPK led to a doubling of the young leaf-blade mass and an increase of 3-4 times in the mass of the leaf-stalk. The minimum and maximum values of yield components at harvesting, as a function of the nutrient supply, were as follows: beet/foliage ratio 2.1 and 6.7, plant density 53 and 92 thousand/ha, mean beet mass 490 and 910 g/bcct, beet yield 42 and 56 t/ha, foliage yield 10 and 25 t/ha. 2. Parameters of industrial quality also changed, deteriorating drastically on over-fertilised soil: digestion 17 and 19.3 %, refined sugar 12.7 and 16.7 %, molasses 2.4 and 4.2 %, toxic N 3.0 and 9.0, K 4.3 and 7.4, Na 0.8 and 2.0 mgcq/100 g. The crude sugar yield ranged from 7.0 to 10.4 t/ha and the refined sugar yield from 6.3 to 9.0 t/ha. 3. Depending on the nutrient supplies of the soil, differences of 2-3 times were observed in the element concentrations of the sugar beet organs, the quality-reducing effect of luxury uptake being manifest in the composition of the young leaf-blades and leaf-stalks and in that of the foliage and beets at harvest. All the organs examined could be used for the diagnosis of the nutrient status. 4. The clement uptake of sugar beet was influenced to the greatest extent by the N supplies, which stimulated the uptake of all the elements. The beets accumulated 2/3 of the N, P and Fe and 3/5 of the K, while the foliage accumulated 56 % of the Mg and 75-76 % of the Na and Ca. The quantity of N absorbed by the foliage + beet ranged from 100 to 508 kg for N, 160 to 355 kg for K (192 to 426 kg K2O) and 8 to 38 kg for P (18 to 87 kg P2O5). The uptake of Na, Mg, Ca, Cu and Zn also increased several times. 5. The specific clement content of 101 beet + the relevant foliage yield exhibited the following minimum and maximum values depending on the treatments: 24-88 kg N, 40-58 kg K. (48-70 kg K2O), 6-42 kg Na, 7-24 kg Mg, 8-21 kg Ca, 2-6 kg P (5-14 kg P2O5), 2-7 kg Fc, 300-400 g Mn, 15-80 g Zn and 22-52 g Cu. The lower specific clement requirements could be used as a guideline for the Hungarian extension service. 6. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analyses indicated that the cell-walls of beets over-fertilised with N and weighing over 1 kg were almost a tenth thinner than those of small N-defieient beets (Figure 1). Such beets are more easily damaged and less resistant to microorganisms causing rotting, so they not only have poorer industrial quality, but are also difficult to store.
|Number of pages||10|
|Publication status||Published - Dec 1 2001|
ASJC Scopus subject areas
- Agronomy and Crop Science