Soil Quality Monitoring Programme: Nematodefauna. Part 3: Sampling in 1995 (arable farmlands on sandy soils)
Landelijk Meetnet Bodemkwaliteit: Nematodenfauna. Deel 3: Bemonstering 1995 (akkerbouwgebieden op zandgrond)
Esbroek MLP van , Alkemade JRM , Schouten AJ
RIVM Report 714801011
A description is given of the nematodes found in the soils of 19 arable farmlands. The average number of nematodes found is very low, falling between the number on earlier sampled sites of forests and cattle farms. The genera Acrobeles, Aphelenchoides, Filenchus and Plectus were found on almost every site. Especially bacterivores are highly representative of the nematode fauna, showing the same abundance as found on the most intensive cattle farms. The trophic diversity index T (1.68) and the maturity index MI(1.48) fell between values for the forest locations, and the extensive and intensive cattle farms on the one hand, and the most intensive cattle farms on the other. The index of richness SR (4.72) and the number of taxa (25) are highest in the soils of the arable farmlands ; while the modified maturity index Sigma MI (1.65) is the lowest there. The other indices like the plant parasite index PPI (2.38), the Shannon-Weaver index H'(2.40) and the index of eveness J'(0.75) are found more or less between those for grasslands and the forests. Nematodes from c-p group 1 ('colonizers') increase in number from the forests through the extensive to intensive cattle farms and arable farmlands. An experiment to determine the most efficient sampling method was also carried out, in which all four bulk samples from four farms were investigated for nematodes, instead of one sample per farm. Indices were calculated from the species composition of the nematode fauna. The variance in components, calculated for the indices, and the variance between and within the farms were compared. Because the variance between the farms was higher, the best sampling strategy seems to be to sample as many as possible farms using one sample per farm.