Effect of different tillage methods on the nutritional status, yield and quality of sugar beets

Optimal nutrition of sugar beets at critical growth stages is one of the crucial factors for the achievement of their highest yield potential. In the present study, it was presumed that reduced systems of sugar beet cultivation had no effect on the plants’ nutritional status at critical growth stages, on their yield or technological quality. In 2012-2013, two series of one-factorial field experiments with different beet crop husbandry were carried out in order to verify this hypothesis. The cultivation systems of sugar beet crops differed in the postharvest cultivation technology, mulch types and seedbed tillage. Conservation tillage systems were compared with the control treatment, which represented the conventional cultivation system with an application of manure and 35 cm deep autumn ploughing. The plant nutritional status assessment was carried out at two dates corresponding to the following growth stages: BBCH 16/17 (6-8 fully unfolded true leaves) and BBCH 39/40 (row closing). Regardless of the methods of tillage or the year of observation, the results showed that the plants at BBCH16/17 stage were well-nourished with macroelements but malnourished with microelements, mainly iron and zinc. The microelement deficiency in the plants was a result of adjusted soil reaction, which varied from slightly acidic to neutral. At the BBCH 39/40 stage, there was a decreasing trend in the content of leaf macronutrients in the no-tillage systems treatments compared to the conventional tillage with the ploughing depth to 35 cm and manure application. The reduced tillage systems in sugar beet cultivation did not result in either a yield decrease or a worse technological quality of roots. The experimental factor had no significant effect on the content of molassegenic compounds in beet roots. A decreasing trend was observed in the content of α-amino nitrogen and potassium when compared to the traditional cultivation system. The study showed that the choice of a cultivation technology is of secondary importance as long as the plant grows in optimal conditions resulting from an appropriate site selection.