Soil pH? How To Track!

Examples of Variation in Groundwater Quality Well # 1 Well # 2 Well # 3 Soil Zone Sand and Gravel Aquifer Limestone or Granite Aquifer Sandstone Aquifer

Irrigation Water Alkalinity concentrations (ppm CaCO3) from Florida 25 20 15 10 5 Frequency % <40 40–80 80-20 120-160 160-200 200-240 240-280 280-320 320-360 360-400 >400

The Goal Is To Achieve A Stable Medium pH Over Time

Plant Growth Cycle Active Growth Establishment Mature

pH Drift Alkaline Water pH “Optimum” Range NH4+ fertilizers Time 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 Alkaline Water pH “Optimum” Range NH4+ fertilizers Time

You Can Use the Water Hardness to Estimate Its Alkalinity CaMg(CO3)2 Ca2+ + Mg2+ + 2CO32- Dolomitic limestone Hardness Hardness and Alkalinity Generally Go Hand-In-Hand but They Are NOT One and the Same You Can Use the Water Hardness to Estimate Its Alkalinity

mg/liter or ppm CaCO3 of alkalinity mg/liter or ppm bicarbonate Alkalinity Terms mg/liter or ppm CaCO3 of alkalinity mg/liter or ppm bicarbonate Milliequivalents alkalinity 1 2 3 4 5 50 100 150 200 250 60 122 183 244 305

The Effect of Water Alkalinity on Media pH and Acid Requirement Sample A Sample B pH = 9 pH = 7 Alk = 50 ppm Alk = 300 ppm Increases growing medium pH Little or no effect on the growing medium pH One drop of acid to get pH 6 Ten drops of acid to get pH 6

Action Steps To Correct High Alkalinity reverse osmosis 480 Alkalinity (ppm) bicarbonate acid injection 180 120 acid fertilizer and/or less lime none

Testing The Soil Solution !

Pour Thru Method Simple technique for measuring pH and EC Charts for recording pH & EC Guidelines for crops Procedures to keep on track

6 or 8-inch saucers are adequate for collecting the leachate

Distilled Water Volumes Pot Size ml oz 4 inch 5 inch 6 inch 6.5 inch 1 Qt 4 Qt 12 Qt 75 100 150 350 2.5 3.5 5.0 12.0

Flats: Use 50 ml Distilled Water

EC Comparisons 1:2 SME PourThru Indication 0 to 0.3 0.3 to 0.8 > 2.3 0 to 0.8 0.8 to 2.0 2.0 to 3.5 3.5 to 5.0 5.0 to 6.0 > 6.0 0 to 1.0 1.0 to 2.6 2.6 to 4.6 4.6 to 6.5 6.6 to 7.8 > 7.8 Very Low Low Normal High Very High Extreme

Initial EC

Crop pH Ranges

Geraniums (6” pinched) 6.0 to 6.6 1/28 6.6 to 6.8 5/01 5.8 to 6.0