Bentonite variations in a peaty-podzolic-gleyish soil under the field model experiment conditions

Changes in bentonite were estimated after having kept it in hor. T2, H, Eih, and E of peaty-podzolic-gleyish (PPG) soil for 1, 3, and 5 years as part of a model field experiment. In the first variant, when montmorillonite is heated at 350°C, its X-ray patterns demonstrate a diffuse scattering (1.0–1.4 nm), which is probably due to the formation of the brucite layer fragments in the interpacket gaps at the expense of magnesium in the initial crystal lattice. When kept in the organogenic layers of soil for 3 and 5 years, it develops a considerable amount of the mineral, which does not swell after being saturated with glycerine. The diffuse scattering at 1.0–1.4 nm disappears after heating at 350°C, but the reflex at 1.0 nm during this treatment remains asymmetric with a gentle sloping towards the smaller angles θ. It can be explained by the partial dilution of the brucite fragments, which developed in the first year, under the conditions of an acidic medium. The changes in the diffraction pattern of hor. Eih, which took place over 1, 3, and 5 years, were similar to those in the organogenic horizons. They were caused by the same reasons as in the organogenic horizons. In the former case, however, thermodynamic measurements allow for the formation of aluminum hydroxide interlayers in the interpocket gaps of montmorillonite as its hydrocomplexes come from the superficial solution.