Abstract:
Biological soil fatigue in horticultural monocultures awakes the highest
interest and presents the highest discrepancy. Different studies associate it with
soil pathogens as causing agents, while others determine it in the lack of these.
This work deals with the assessment of fatigue existence, a phenomenon which
can be appreciated in the field, but a numerical model that provides data about
yield losses and lack of plant vigour has not been found. Trial planning consisted
of adding fresh organic matter through biodisinfection techniques and providing
knowledge about the phenomenon and its relation with the content of organic
matter and soil microbiota. For this reason, soils of two greenhouses were
compared, the differences between them were the type of crop (cucumber and
tomato respectively) as well as the supplying or non supplying of organic
amendments. The content of organic matter and the soil or telluric microbiota
(fungi, bacteria and oomycetes) in the soils were studied, as well as its effect on
cucumber and tomato seedlings under controlled conditions. The results showed
that fatigue appeared in soil with low content of organic matter, which showed at
the same time lower density and diversity of fungal population. The addition of
fresh organic matter seems to reconstitute the productive capacity of the soils, and
this mitigates the fatigue and monoculture effects.
