A Fast Procedure to Estimate Hydraulic Characteristics of Greenhouse Substrates from One-Step Outflow Data

An improvement to an iterative method for the simultaneous determination of soil hydraulic properties from One-Step data has been developed, inserting in the optimization algorithm some parameter among which ‘r’ (residual water content) improved the procedure. Soil hydraulic properties were characterized by the Brooks and Corey equation for water retention, and by the Kozeny power equation for hydraulic conductivity. The iterative procedure was examined for a particular class of soil such as substrates for container cultivation represented by three mixes of peat and pumice. Estimated hydraulic conductivity was compared with the estimation obtained from the Van Genuchten-Mualem equation. The comparison showed a very high similarity between the two curves. Applying One-Step procedure, the duration of experiments can be decreased to one week, compared with the standard duration quantifiable in three or more weeks.