NON-TRADITIONAL AMELIORANTS - Fertilizers: Components, Uses in Agriculture and Environmental Impacts - page 208

Figure 7. Effect of bentonite clay ploughed in the 0-5 cm soil layer on the available moisture content in
the arable layer, % deviations from control (no ameliorant).
Figure 8. Effect of bentonite clay ploughed in the 0-5 cm soil layer on crop yields, % deviations from
control (no ameliorant).
In all years of observation creating a mulch layer of this ameliorant contributed
statistically significant increase grain yields (Figure 8). By year the raise of crop yield varied
greatly, as dependent on the biological characteristics of culture, the weather conditions and
the period since the establishment of mulch layer. The most responsive cereal crop to enter
bentonite clay in the soil layer of 0-5 cm was barley. The least of all responsive culture was
winter rye, as it had a well-developed root system and it less dependent on soil fertility.
Mulching has the greatest impact on crop yields in dry growing season, especially if the
observed soil drought.