Effect of airdrying, γ-irradiation and chloroform fumigation of soil on extractability of trace elements

Abstract

In many instances soils are routinely air-dried and sieved prior to chemical analysis to permit ease of handling and decrease variability. Such drying, however, can increase the extractability of some elements, for example, the amount of P extracted by 0'5 m-NaHCO3 (Brookes, Powlson & Jenkinson, 1982). Much of the increased P is derived from soil micro-organisms killed by the soil drying (Brookes et al.1982). Similarly, much of the flush of C and N mineralization that occurs after rewetting of dried soils can be derived from killed soil micro-organisms (Jenkinson & Powlson 1976; Marumoto et al.1977; Marumoto, Anderson & Domsch, 1982).