Liebhard


Die Bodenkultur - Journal for Land Management, Food and Environment

E. Liebhard:

Influence of primary tillage on yield and yield characteristics of corn (Zea mays L.) in the centre of Upper Austria (part 7)

Summary

The effects of cultivation of the top soil at various depths with either plough, field cultivator and rotary tiller on the yield performance of corn within a four-field crop rotation were examined. The experiment was carried out from 1981 to 1992 in a semi-humid climate region in Upper Austria. The type of soil is a deep medium-heavy calcium-free loose sedimentary brown earth.

The results achieved during a 12-year period of experimentation with corn demonstrated that a distinction should be made between short and long term effects. Because of favourable location conditions and the existing high cultivation intensity no significant differential effect of the cultivation method on yield performance was detected in the first four years.

The shallow ploughless tillage method used over a longer period of years in combination with a spell of bad weather during sowing season led to flooding and to a reduction of sprouting of up to 13 %. A measurable increase in soil density, a reduction of the pore volume (especially of the fraction of large pores), and a decrease of aggregate stability led to a reduced vegetative biomass production. The grain yield on the ploughed plots was about 87 dt/ha. Yield was reduced up to 17 % on the plots with diminished cultivation intensity. Under the existing soil condition high corn grain yield can be attained only by turning the soil once or twice during the crop rotation. A deepening of the plough furrow from 17 to 30 cm caused no improvement in production conditions.

Key words: Primary tillage, corn, grain yield, soil physical parameters.