SIMPLIFIED METHOD TO DETERMINE THE BASE-N EUTRALIZING CAPACITY OF STRONGLY ACIDIFIED SOILS

The base-neutralizing capacity (BNC) is an important property to chara cterize acid soils. The BNC can be reliably determined by soil-base ti trations (BNCtit). But these methods are work-expensive, and a large a mount of soil material is needed. Such a large amount of soil material is not available if the soil is sampled by a hand-auger (e.g. mapping , areal investigations). Known buffer methods require less soil materi al, but have some shortcomings. Therefore, the well known Schachtschab el-method with calcium acetate buffer was developed for the applicatio n to strongly acidified soils. BNC values measured by the developed ca lcium acetate method (BNCac) agreed nearly perfectly with BNCtit value s of 59 mineral soils. The BNCac slightly overestimated (< 10%) the BN Ctit of 10 samples of humus layers. Furthermore, small soil samples (d own to 1 g soil), wide soil:solution ratios, and integration of pH (H2 O) measurements into the determination of the BNCac yielded reliable B NCac values. Thus, the BNCac-method may be recommended as a simple and reliable method to determine the BNC of acid soils, especially if onl y a small amount of soil material is available.