Mineral nutrient analysis
To determine if HLS enhanced nutrient uptake, the nutrient depletion from solutions was measured at the end of the two-month experimentation period. Plant samples were ground in a Wiley mill to a particle size of 1 mm and then analyzed for their mineral content following dry ashing. Macronutrient (P, K, Ca, S) content were determined by HPLC (DionexDX100) except for nitrogen
which was determined using a Leco CHN elemental analyzer.
Microelements were analyzed by atomic absorption spectrometry (Perkin Elmer).