plant tissue tests ref name adv class wikitable element role ionic form low range ppm high range ppm common sources comment nitrogen essential macronutrient p p ref name jones ref name adv kno sub sub nh sub sub sub sub ca sub sub sub sub hno sub sub nh sub sub sub sub sub sub nh sub sub sub sub hpo sub sub nh interferes ca sup sup uptake toxic plants used major nitrogen source ratio n nh n ''wt '' sometimes recommended balance ph nitrogen absorption ref name jones plants respond differently depending form
Applied science Agriculture Hydroponics