Physico-chemical properties of peat-reduced press-pot substrates

The data was processed in the manuscript "Reducing peat in substrate mixture formulations for press pots using the Taguchi method".
Here, the Taguchi design was assessed as an alternative to classical experimental design for identifying optimal peat-reduced substrate mixtures for press-pots. The substrates mixtures were composed by 50 % v/v of a professional press-pot substrate (100 % peat) with varying shares of green compost, bark compost, wood fibre and rice husks ("Composition of the press-pot substrates.xlsx"). After mixing, press pots were formed from each substrate and received an initial fertilization of 50 mg N (142.85 mg NH4NO3). The press pots were stored (randomized) in a climate cabinet at 20°C and 80 % air humidity.

The following parameters were assessed: density, pH-value, salt content, maximum water holding capacity (WHCmax), stability and mineral N (nitrate and ammonium). Methods and units are described in the table "Measured parameters.xlsx". The mineral N content was measured at three dates: one day after the initial fertilization, seven and 14 days after the first measurement of mineral N. An overview on the dates of the measurements is given in the table "Dates of the measurments.xlsx". The data ("Properties of the press-pot substrates.xlsx") lists the results for the selected physical and chemical properties of the press-pot substrate mixtures for each parameter and each repetition (five repetitions for all parameters but WHCmax).
The aims of the research were to assess (a) if the combinations of the selected raw materials are suitable as press pot substrates in vegetable production and (b) if the Taguchi design is appropriate for the quality assessment of substrate blends and for the creation of algorithms to predict major characteristics of substrate mixtures.