Monitoring Chemical Properties of Growing Media with Small Soil Solution Samplers
in HortScienceHydrophilic polymer tubes (2.5 mm OD, 1.4 mm ID, 10-cm length, 0.1-mm pore diameter) attached to PVC hose were used to extract solution from soilless media at container capacity and analyzed for pH, EC, NO3-N and NH4-N. Media chemical properties were also analyzed by the Saturated Media Extract (SME) and Pour-Through (PT) methods. Extraction and analyses were conducted in peat: vermiculite (PV) and peat: perlite (PP) media irrigated for 1 week with Hoagland solution at 0.25, 0.5, 1, 2 and 4x. A 10-mL syringe was used as the vacuum source (48.1 ± 0.5 kPa) for the solution samplers (SS), yielding ≈2–5 mL of solution over a 3-min period. Simple correlation coefficients for EC, NO3-N and NH4-N between SS and SME and PT were high (>0.99). When measured by PT, these chemical properties were similar to SS (within 1% to 6%), whereas SME values were much lower than SS (12% to 15% and 35% to 38% in PV and PP media, respectively). Correlation coefficients for pH were lower than in other chemical properties, particularly in the PV medium. With an estimated life of ≈6 months in soil, SS are excellent monitoring tools for mineral nutrition research and horticultural crop production.
