Effects of different intensities of cultivation on the Collembola of agricultural soil
1994
Heimann-Detlefsen, D. (Biologische Bundesanstalt fuer Land-und Forstwirtschaft, Braunschweig (Germany). Inst. fuer Pflanzenschutz in Ackerbau und Gruenland) | Theiss, S. | Heimbach, U.
The effects of a graded intensity of agricultural cultivation on Collembola were recorded from 1987 to 1989 on the experimental fields 'Ahlum' of the Federal Biological Research Centre for Agriculture and Forestry. The crop rotation followed the order winter-wheat, winter-barley, sugar beets. The four intensities of cultivation differed mainly in the application of pesticides and N-fertilizer, and therefore also in the density of vegetation of cultured crops and accompanying weeds. Within the period of research, a total of 40 species of Collembola were recorded. Isotoma notabilis, Isotomurus palustris and Folsomia fimetaria were almost always the dominant species. The mean density of individuals of the collembola was 230 ind. per 0.01 qm. The effects of the different intensities of cultivation showed up mainly in two opposed trends: the effects of the frequency of application of herbicides and the influence of the supply of nutrients. In the more extensive variant, with a large proportion of weeds and low density of cultivated crops, Anurida pygmaea and Sphaeridia pumilis had significantly higher densities of individuals in every investigation period than in the two variants with high intensities of cultivation. The function of these two species as bioindicators was discussed in this context. In addition, in the variants treated less intensively with pesticides, the proportion of the mainly phytophagous species of the total number of collembola was greater, as weeds were available as resource of food. The increased supply of nutrients in the middle variants led to a better coverage of plant of both cultivated crops and weeds, and thus, especially under moister conditions of weather, to an increase in the number of species of collembola
显示更多 [+] 显示较少 [-]