Liebhard 2


Die Bodenkultur - Journal for Land Management, Food and Environment

P. LIEBHARD:

Influence of primary tillage On yield and yield characteristics of Winter wheat (Triticum aestivurn L.) in the centre 0f Upper Austria (part 6)

Summary

The influence on yield and yield stability of long-term, different primary tillage methods at varying depths within a four-field crop rotation was examined.

This testing was based on the results of previous works using selected biochemical and physical parameters. On the medium-heavy, loam and clay rich soil in a semihumid climate, it could be proven that the yield results for winter wheat are equal, whether using tillage systems with reduced intensity or conventional tillage methods. The compression of the soil caused by cultivation can be countered effectively by means of periodic ploughing at topsoil depth for root-crops.

The twelve-year test results (1981 to 1992), after three rotations, show that the wheat plants are iduenced in all phases of their development by the physical soil changes (density, Pore volume, Pore distribution, aggregate stability) caused by varying tillage methods. These soil changes, however, have a significant but relatively slight effect on the grain yield. The number of germinated plants decreased about 3 to 11% with the increasing duration of ploughless tillage. The significant iduence of the number of germinated plants on the grain yield remained even under optimum conditions during the sprouting phase from the third rotation On.

In the yearly average, the highest yields of 70.9 dt/ha for wheat were obtained on the plots rotary-tilled and on the plots ploughed to the customary depth of 24 cm for the root crops. The grain yield decreased by 1.7 to 3.1% after yearly ploughing. The harvest quantity diminished between 4.1 and 4.7% after medium or deep grubbing treatment. The harvest was reduced by 6.1% after annual flat grubbing at only 17 cm depth. The regularly lowest grain yield – on average 10.9 % less - was harvested on rotary-tilled plots.

There were more distinct annual fluctuations in the accrued amount of straw, but On the average, the straw yield was similar to the grain yield.

Key-words: Primary tillage, winter wheat, yield Parameters, grain yield, straw yield.