29-03-2021, 03:48
pH and Alkalinity
Alkalinity and pH are two important factors in determining the suitability of water for irrigating plants. pH is a measure of the concentration of hydrogen ions (H+) in water or other liquids. In general, water for irrigation should have a pH between 5.0 and 7.0. Water with pH below 7.0 is termed "acidic" and water with pH above 7.0 is termed "basic"; pH 7.0 is "neutral". Sometimes the term "alkaline" is used instead of "basic" and often "alkaline" is confused with "alkalinity".
Alkalinity is a measure of the water's ability to neutralize acidity. An alkalinity test measures the level of bicarbonates, carbonates, and hydroxides in water. These compoounds get into the water from the geologic materials of the aquifer from which the water is drawn, such as limestone and dolomite. Test results are generally expressed as "ppm of calcium carbonate (CaCO3)". The desirable range for irrigation water is 0 to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most plants.
Irrigation water tests should always include both pH and alkalinity tests. A pH test by itself is not an indication of alkalinity. Water with high alkalinity (i.e., high levels of bicarbonates or carbonates) often has a pH value of 7 or above, but water with high pH does not always have high alkalinity. This is important because high alkalinity, not pH, exerts the most significant effects on growing medium fertility and plant nutrition.
A UMass Extension greenhouse water study found that pH in the range of 7-8 is common in most water sources found in Massachusetts. These higher pH levels are typically not a problem unless the alkalinity exceeds the acceptable range. High pH/high alkalinity water is common in Berkshire County and sometimes is found in other parts of the state.
Water Quality for Crop Production
Water Quality: pH and Alkalinity
pHGreenhouseCrops.pdf (Μέγεθος: 261,11 KB / Λήψεις Αρχείων: 404)
Water Analysis
ghbmpwateranalysis.pdf (Μέγεθος: 100,8 KB / Λήψεις Αρχείων: 306)
Alkalinity and pH are two important factors in determining the suitability of water for irrigating plants. pH is a measure of the concentration of hydrogen ions (H+) in water or other liquids. In general, water for irrigation should have a pH between 5.0 and 7.0. Water with pH below 7.0 is termed "acidic" and water with pH above 7.0 is termed "basic"; pH 7.0 is "neutral". Sometimes the term "alkaline" is used instead of "basic" and often "alkaline" is confused with "alkalinity".
Alkalinity is a measure of the water's ability to neutralize acidity. An alkalinity test measures the level of bicarbonates, carbonates, and hydroxides in water. These compoounds get into the water from the geologic materials of the aquifer from which the water is drawn, such as limestone and dolomite. Test results are generally expressed as "ppm of calcium carbonate (CaCO3)". The desirable range for irrigation water is 0 to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most plants.
Irrigation water tests should always include both pH and alkalinity tests. A pH test by itself is not an indication of alkalinity. Water with high alkalinity (i.e., high levels of bicarbonates or carbonates) often has a pH value of 7 or above, but water with high pH does not always have high alkalinity. This is important because high alkalinity, not pH, exerts the most significant effects on growing medium fertility and plant nutrition.
A UMass Extension greenhouse water study found that pH in the range of 7-8 is common in most water sources found in Massachusetts. These higher pH levels are typically not a problem unless the alkalinity exceeds the acceptable range. High pH/high alkalinity water is common in Berkshire County and sometimes is found in other parts of the state.
Water Quality for Crop Production
Water Quality: pH and Alkalinity
pHGreenhouseCrops.pdf (Μέγεθος: 261,11 KB / Λήψεις Αρχείων: 404)
Water Analysis
ghbmpwateranalysis.pdf (Μέγεθος: 100,8 KB / Λήψεις Αρχείων: 306)
