admin - September 19, 2016
Covering the basics of how we grow hydroponic strawberries off the ground. Showing the growing medium, watering/nutrient supply system, how to plant & harvest.
Richmond, Nelson NZ
Nutrients should contain the following minerals.
Nitrogen, Potassium, Phosphorous, Calcium, Magnesium, Sulphur, Sodium, Chloride, Silicon, Iron, Manganese, Boron, Copper, Zinc, Molybdenum.
Nitrogen 2.6 to 3.5% Phosphorous 0.25 to 0.35%
Potassium 1.0 to 2.0% Calcium 0.7 to 1.5%
Magnesium 0.25 to 0.4% Sulphur 0.15 to 0.35%
Iron 100 to 200 ppm Manganese 200 to 500 ppm
Boron 30 to 100 ppm Copper 5 to 12 ppm
Zinc 30 to 80 ppm
Plant growth promotants are often added to the nutrients to produce quality growth during periods of poor conditions, e.g. in winter under low light.
The growth promotants, Agronomix at 20 gms per 20 Kg of dry powder mix, and SGP at 500 mls per 20 Kg dry powders may be added to drum ‘B’.
Nutrient formulation is blended to suit the water supply, so a water mineral analysis is essential for optimum formulation.
Downwards pH correction is usually with Phosphoric Acid, but there may be situations where Phosphoric/Nitric Acid mixes are used, or even straight Nitric Acid at times, especially if the water supply has a high pH, above 7.8 for example.
Upwards pH correction is always carried out with Potassium Hydroxide. Common name Caustic Potash.
Note… all pH correctors are added in a very weak form; never use full strength acid or alkali to adjust nutrient solution. Dilutions of 500 to 1 with water are normal.
reference – http://pgohort.co.nz/resources/1/crop%20data/Strawberry%20data.pdf