Characteristics of growing media mixes and application for open-field production of strawberry (Fragaria ananassa)

- Nutrient, pH, and salinity levels in growing media were suitable for strawberry.
- Coir showed the highest water content at saturation and after free drainage.
- Strawberry yields in coir and peat-perlite were comparable to grower standard.

Growing media are widely used for strawberry production in protected environments. Due to increasing restrictions on the use of soil fumigants, there is a need to investigate production of strawberry fruits in open fields using substrate media. The objectives of the study were to characterize chemical and hydraulic properties of a number of selected growing media mixes and to evaluate them in a two-year field study for strawberry production in open fields. The growing media mixes were 100% coconut coir, a peat-perlite (PP) mix, a peat-rice hull (PR) mix, and a peat-coir-rice hull (PCR) mix. Results indicated that major macro- and micro nutrient element concentrations, pH, and salinity found in these growing media, after supplemental fertilization, were in recommended ranges for strawberry production. Compared to field soil, higher water content values were found for these growing media mixes at saturation and after free drainage. Among these media mixes, 100% Coir showed the highest water content values at saturation (0.95 cm3 cm−3) and after free drainage (0.51 cm3 cm−3). The field study also demonstrated the most vigorous vegetative growth in Coir by showing higher values in plant canopy size and biomass dry weight. In year 1 field experiment, marketable strawberry fruit yields from Coir, PP, and PR averaged 41,640 kg ha−1 which was not significantly different from the soil beds. Marketable strawberry yields from the year 2 Coir and PP treatments averaged 48,520 kg ha−1, which was also not significantly different from the grower standard practice in field soils. The year 2 yield was higher than year 1 because of longer harvesting season and more favorable weather conditions for strawberry growth. The study demonstrated that certain growing media mixes such as PP or the 100% Coir possess the needed chemical and hydraulic properties for plant growth and the 100% Coir could be used as a promising substrate material for open-field production of strawberries. Additional work is needed to optimize the irrigation and fertilization regimes to reduce the volume of growing media needed per plant and to evaluate the reuse of the substrate media to reduce production cost.