Effects of white grubs on soil water infiltration.

Water infiltration rates k were measured in mesocosms with soil and "white grubs" of Ancognatha falsa (Arrow) (Coleoptera: Melolonthidae). Three third instars of A. falsa and three adult earthworms Pontoscolex corethrurus were selected, weighted, and introduced into the mesocosms setting three treatments: soil + A.

ABTS assay of phenol oxidase activity in soil.

Phenol oxidases (PO) are involved in degradation of many recalcitrant aromatic compounds and may be sensitive to some pollutants. Hence, their activities may be a useful indicator for evaluating soil quality and health. To this end, the aim of this study was to develop a simple method to assay PO activity directly in bulk samples by spectrophotometric test using 2,2'-azinobis-(-3 ethylbenzothiazoline-6-sulfononic acid) diammonium salt (ABTS) as the substrate.