Effects of boring systems and of borer species on the N(min)-values of
soil samples taken from 0 cm to 30 cm, 30 cm to 60 cm and 60 cm to 90
cm depth were investigated. At the experiment station Ihinger Hof (Ho
henheim University) during autumn and winter 1990/1991 at several date
s soil samples were collected from 2 different fields. At first the co
rrectness of the N(min)-values of samples taken by hand with a several
-piece borer system was examined. To this method of reference 4 boring
systems (Hand/hammer, Dutzi, N-caterpillar, Drilling-machine) in comb
ination with different one-piece borer species were compared. - Import
ant results were: particularly at strong nitrate gradients high over-e
stimations of the N(min)-values resulted from the boring systems ''Han
d/hammer'' and ''Dutzi''. With the system ''Drilling-machine'' combine
d with a drilling borer an underestimation occurred. In contrast to th
ese results the N(min)-values of soil samples taken by the system ''N-
caterpillar'' corresponded very well with the values of the method of
reference. Except the drilling borer the used borer species had no imp
ortant effect on the N(min)-values of soil samples.