A comparative study has been made to investigate the influence of organic and chemical fertilizers on abundance and species diversity of soil microarthropods at greenhouse biotopes in Gharbia Governorate. The study was extended for one year (May 2002-April 2003). The soils of the two greenhouses were cultivated with various plants (pepper, cucumber and tomato). Ten soil samples were taken randomly each month, by metal cuboid sampler. Extraction of soil microarthropods was carried out using modified Berlese's funnels. K-dominance curve using species rank and cumulative abundance as well as species diversity were adopted. The results revealed that the total number of extracted oribatid mites and Collembola were 18 and 3 species respectively; three oribatid species were dominant in chemical fertilizer treated greenhouse (CFTG) e.g. Scheloribates latipes, Rhysotritia a. aruda, and Cilioppia dalgamonica. However, in organic fertilizer treated greenhouse (OFTG), the same three species of oribatids in addition to two other species, (Scheloribates confundatus and Hoplophorella scapillata) were recorded to be the dominant ones. The present results reveal that both studied greenhouses showed the same pattern of the cumulative ranked abundance for oribatid species. The average annual population densities of the total oribatid mites were higher in CFTG than in OFTG. On the contrary, collembolan abundance was two time and half more in OFTG than in CFTG. Species diversity was rather constant in chemical and organic fertilizer treated green house (2.23 and 2.17, respectively). In conclusion, the convergence and divergence between and within greenhouse communities, as their abundance, are related to the different response of microarthropods toward different types of fertilizers.
Key words: Greenhouse, Microarthropods, Fertilizers, Abundance, Species diversity
|
