SOIL-STRUCTURE EVALUATED BY GAMMA-RAY ATTENUATION

The monoenergetic gamma-ray attenuation methodology is applied to stud y the structure of two well-aggregated Brazilian soils. The methodolog y distinguishes pores that comprise the space between aggregates and p ores present only within aggregates. A comparison of the results with those obtained by conventional methodologies, indicates very good agre ement. It is concluded that the methodology is very convenient to moni tor the spatial distribution of inter- and intra-aggregate porosities since it is a nondestructive methodology and allows the evaluation of porosity changes that may occur during long periods of soil cultivatio n. Once having obtained a calibration regression for a given soil laye r, total intra- and inter-aggregate porosities can be obtained from so il bulk density data only. (C) 1998 Elsevier Science B.V. All rights r eserved.