The length of external hyphae in bulked soil samples was determined after the hyphae had been extracted using a modification of a membrane filter technique (Abbott, Robson & De Boer, 1984). A 2 g subsample was taken from each soil sample and blended with 500 ml of deionized water for 20 s in a kitchen blender. This solution was washed through a 500 um
mesh sieve into a 1 1 beaker and left to stand for 60 s. The washings were decanted into another 1 1 beaker and gently stirred while two 25 ml aliquots were removed. These aliquots were filtered under suction through a 1-2 ,am millipore filter. The filter was cut