The Effects of a Simplified Crop Rotation
Research has shown that as a result of long-lasting monoculture cultivation, growth retardant
bioactive substances accumulate in the soil. This accumulation is a crucial factor that may cripple
the effectiveness of agricultural production. Among the above-mentioned harmful bioactive substances,
the worst are phenolic compounds and flavone derived glycosides. These substances are freed by soil
fungi during decomposition of post-harvest leavings and are created during the decomposition of
young seedlings in the presence of bacteria. Their concentration in the soil not only causes
lowering of crop yield by 15–30%, but also changes the composition and functioning of soil
microorganisms. In turn, this worsens the quality of newly formed humus. In the soils where
crop monoculture is prevalent, a general impoverishment of microflora and fauna occurs.
This is usually accompanied by an increase in the share of pathogens (nematodes, disease causing
fungi) and species specific plant pests. The observed phenomena of crop yield decline, degradation
of soil humus, proliferation of the pathogens and plant pests and the increase in the quantity of weeds
prove that over-simplification of crop rotation and long-term specialization in one type of crops
should be abandoned.
