Sample Information
This section contains sample information provided by the client, including sample identifier, description of intended use, solution use code, and grower comments.
Nitrogen
This section reports the total concentration of inorganic nitrogen and the individual concentrations of inorganic nitrate-nitrogen (NO3-N) and ammonia-nitrogen (NH4-N), which sum to the total inorganic nitrogen concentration. Results are reported in parts per million (ppm) which is equivalent to mg/L.
Other Plant Nutrients
Concentrations of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), and boron (B) are reported in parts per million (ppm) which is equivalent to mg/L.
Sodium, Chloride and Aluminum
Sodium (Na) and chloride (Cl) are elements that may be important for plant nutrition but are more often detrimental to plant health in excessive levels. Aluminum (Al) is not a plant nutrient and may create toxicity when soil or substrate pH is excessively low. Aluminum also plays a role in coloration for ornamental crops such as hydrangea.
Other Parameters
EC (Electrical Conductivity) is reported in units of mS/cm. It measures the total quantity of dissolved salts (ions) in solution. It may be used as a general evaluation of the total nutrient concentrations available to plants. However, it also includes elements such as sodium (Na) and chloride (Cl), which increase EC without providing nutritional value. In addition, excessively high EC will burn plant roots regardless of the whether the ions are required for plant nutrition.
SS (Soluble Salts) is the same as EC, but is expressed in units of 10-5 S/cm.
pH is the level of acidity or basicity as measured by the amount of hydrogen ions (H+ ) in solution. It ranges from 0 (acidic) to 14 (basic) on a logarithmic scale; 7 indicates neutrality. It can reduce the availability of micronutrients (Fe, Mn, Zn, Cu, B) when pH is high (>6.5) and the availability of macronutrients (N, P, K, Ca, Mg, S) when pH is low (<5.0). It also impacts the efficacy of pesticides.
SAR (Sodium Adsorption Ratio) indicates the ratio of Ca+ Mg: Na. It is useful in predicting the potential of Na to accumulate in the soil or soilless media and damage plant root systems. Ca and Mg may ameliorate the negative effects of Na in soil or substrate systems. Generally, SAR values >10 indicate the potential for Na damage to plant health.
Total alkalinity (CO3 + HCO3 ) is a measure of water's ability to neutralize acids or resist change in pH (pH buffering capacity). It is reported as ppm calcium carbonate (CaCO3 ). It indicates the tendency of irrigation water or nutrient solutions to increase soil or substrate pH. In some plant production systems, alkalinity must be neutralized to avoid increasing substrate pH to levels that reduce micronutrient availability or do not support plant growth.
Hardness indicates the amount of Ca and Mg in water, expressed as ppm of calcium carbonate (CaCO3 ). It is useful in evaluating water for potential to build up scale or for compatibility with animal medicines.
Acid Requirement indicates the number of ounces of battery acid (35% sulfuric acid) to apply to each 100 gallons of water to lower alkalinity to a desirable level. The AR on the report is the amount required to neutralize 100% of the alkalinity above 100 ppm CaCO3 in the water sample.
Agronomists Comments
If the client provides information on the submission form regarding the intended use of the water or nutrient solution sample, an NCDA&CS agronomist will review the results, point out any parameter value that may be detrimental to the intended use, and offer suggestions for management.
This page was last modified on 04/17/2024