A physico-chemical process has been developed to transform and enhance lignocellulosic waste in liquid humic extracts: humic-like
substances (HLS). The aim of this study was to determine the effects of HLS on plant physiology in order to consider their agricultural
use as organic fertilizers. The effects of HLS were evaluated on maize seed germination, and their impact on growth, development and
mineral nutrition was studied on maize plants cultivated under hydroponic conditions. The experimental results showed that HLS do not
increase the percentage and rate of germination but enhance the root elongation of seeds thus treated. Positive effects were also observed
on the whole plant growth as well as on root, shoot and leaf biomass. These effects can be related to the high water and mineral consumption
of plants undergoing this treatment. The high water efficiency indicated that such plants produce more biomass than non-treated
plants for the same consumption of the nutrient solution. Furthermore, the use of HLS induced a flowering precocity and modified
root development suggesting a possible interaction of HLS with developmental processes. Considering the beneficial effect of HLS on
different stages of plant growth, their use may present various scientific and economic advantages. The physico-chemical transformation
of sawdust is an interesting way of enhancing organic waste materials.