Effect of different soil treatment methods and weed control on microbiological properties of soil and potato yield

摘要

In a field experiment conducted on a leached brown soil in Malice, near Zamosc, Poland in 1999-2000 the effect of tillage and weed control on soil microbiological factors was investigated. With regard to soil tillage a conventional tillage, a ridge tillage and a reduced tillage were compared while the different variants of weed control were a mechanical, a mechanical-chemical with metribuzin and a chemical treatment with linuron and metribuzin. The soil was sampled after planting, at flowering and before harvest and microbiological properties determined. The results showed that the methods of soil tillage and weed control had no significant effect on the microbial counts in the soil. However the highest activity of dehydrogenase (indicator for biological activity) was found in treatments with ridge or reduced tillage and by using mechanical weed control. Conventional soil tillage and chemical weed control with herbicides reduced the activity of the dehydrogenase. A "Biological Index of Soil Fertility" which was calculated from microbial counts, organic matter content and adsorption capacity, was not influenced by the investigated factors. The yield of potato tubers was highest by using ridge or conventional soil tillage in combination with mechanical and mechanical-chemical weed control. The potato yield was negatively correlated with the count of bacteria and actinomycetes.