Liebhard


Die Bodenkultur - Journal for Land Management, Food and Environment

E. Liebhard:

Influence of primary tillage on yield, yield characteristics and selected quality criteria of sugar beet (Beta vulgaris L. ssp. vulgaris var, altissima Doell) in the centre of Upper Austria (part 8)

Summary

In a long-term experiment from 1980 to 1992, on a medium-heavy soil in a semihumid climate, the effects of several cultivation (tillage) methods at varying depths with a rotation of crops every four years were investigated. It could be proved that a distinction must be made between short and long term effects on yield as well as on quality. A flat, ploughless tillage resulted in compression damage in the area of the topsoil basis. In the first and partly also in the second 4-year testing period the negative consequences were still concealed, mainly by yearly ploughing previous to the comparative experiment. Surplus yields of 5 % to 10 % on the ploughed plots were attributed in the first 8 years to a slightly higher number and a greater individual weight of the sugar beet. Among the variants there were differences of about 15 % in the number of plants from the third rotation onwards. Subsequently, with reduced cultivation intensity; the yield differentiation increased to about 20 % due to fewer plants and single beets of lower average weight. A deepening of the furrow from 24 to 30 cm on the medium-heavy clay soil led to not measurable increase in white sugar yield. Only from the third rotation the improved rooting in deeper soil layers, which resulted from ploughing, lead to a substantially favourable shape of the beet, i. e. decrease of root fanging and higher white sugar content.

The influence of primary tillage on qualitative parameters can be better judged by the trend from co variations of selected physical soil properties mentioned in previous papers, than by average values.

The results also show that at the cited location, the primary tillage method should be adapted to the specific requirements of the cultivated crop. Furthermore, over longer periods of time, within a well performed rotation of crops, a one or two time ploughing or hoeing of the soil at 20 to 25 cm depth is sufficient for growing sugar beet.

Key words: Primary tillage, sugar beet, beet yield, yield structure, quality.