Traditional ploughing cultivation can contribute to soil erosion as well as to other symptoms of soil degradation, leading to a decline in its biological and production potentials. An alternative to conventional tillage is offered by simplified cultivation systems consisting of shallower and less intensive interference into the soil physical structure or even complete abandonment of cultivation treatment. The aim of the performed investigations was to ascertain the impact of a long-term application of simplifications in soil tillage on select soil chemical and microbiological properties under sugar beet cultivation employing two watering combinations: natural distribution of precipitation and sprinkling. Conventional ploughing tillage was treated as reference. The research hypothesis assumed that the application of simplifications in the pre-sowing soil cultivation of sugar beets contributes to the increase in soil organic carbon content and soil fertility. Its microbiological activity and sprinkling also can modify this effect.
Experiments were carried out for a period of four years in conditions of long-term application of three tillage systems (conventional tillage, simplified cultivation, and direct sowing). Select soil chemical (pH, C_org., total N) and microbiological (total bacterial counts, numbers of oligotrophs, copiotrophs, actinomycetes and fungi, plus activity of dehydrogenases and acid phosphatase) parameters were analyzed.
The microbiological indices analyzed in this study nearly always spoke in favour of simplifications in soil tillage or complete abandonment of cultivation treatments. In successive years of experiments, almost all the analyzed parameters assumed the lowest values in conditions of ploughing cultivation and the highest ones in direct sowing. Sprinkling and fertilization modified this rule, whereas the level and directions of this impact varied and depended on weather conditions.