Fig. 4. Relationships between pesticide content in soil, M, and the solution volume per unit mass of soil, (/), in the region x > x* for monocrotophos and dichlorvos. Note that for dichlorvos, data on samples taken from the dry end of the column (at _n) were excluded from the regression analysis. C_n = initial liquid-phase concentration; Q_n = initial sorption by soil; _n = initial water content; x = distance; x* = plane of separation.