NON-TRADITIONAL AMELIORANTS - Fertilizers: Components, Uses in Agriculture and Environmental Impacts - page 205

Figure 4. Effect of bentonite clay ploughed in the 0-5 cm soil layer on the content of organic matter in
the arable layer, % deviations from control (no ameliorant).
Figure 5. Effect of bentonite clay ploughed in the 0-5 cm soil layer on the content of labile phosphorus
in the arable layer, % deviations from control (no ameliorant).
The mixing of bentonite clay in the soil layer of 0-5 cm did not show a clear-cut effect on
the exchangeable potassium content. Differences with control over the observation period
varied in different directions, and in most cases do not prove statistically (Figure 6).