@masterthesis{Li, type = {Bachelor Thesis}, author = {Li, Shiwei}, title = {Influence of long-term organic and conventional farming on soil microbial properties}, school = {Hochschule Rhein-Waal}, abstract = {In order to find out how different farming system influence microbial biomass and therefore influence the long-term soil fertility and soil quality, this study analyzed the impacts of conventional integrated and organic farming systems on soil microbiological parameters using soil samples from the DOK long-term field experiment (Switzerland). Farmyard manure fertilizer is applied to bio-dynamic (D), bio-organic (O) and conventional farming system (K) with two different intensities. Besides, there are a conventional mineral fertilizer received system (M) and an unfertilized control plot (U). The chloroform fumigation extraction (CFE) method and quantitative polymerase chain reaction (qPCR) test were applied for detection and quantification of soil microbial biomass along with some other tests in physical, chemical and biological aspects. Soil pH tends to increase by applying farmyard manure. Metabolic quotient (qCO 2 ) revealed a lower level in the manured system though there was no significant difference between conventional and organic system. On one hand, D treatment achieved the highest values regarding microbial biomass carbon, nitrogen and phosphorus, and the highest gene copies number of detected microbial domains. On the other hand, higher concentration of microbial biomass sodium, potassium, manganese, silicon, nickel and zinc were found in M and K system. Contrary to expectation, the soil organic matter content between different treatments had only a little difference. In general, each tested soil quality parameter was affected by the type and quantity of fertilizer used to a different extent, among which the soil microbiological parameters showed more pronounced difference compared with soil physical parameter, pH and soil organic matter content. In short, organic farming system had greater potential to maintain soil fertility and improve soil quality than conventional farming system in the long term; while the comparison between two organic systems emphasized the beneficial influence from applying compost manure and bio-dynamic additives.}, language = {en} }