Hoagland solution
The Hoagland solution is a hydroponic nutrient solution that was developed by Hoagland and Snyder in 1933,[1] refined by Hoagland and Arnon in 1938[2] and revised by Arnon in 1950.[3] It is one of the most popular solution compositions for growing plants (in the scientific world at least) with more than 16,000 citations listed by Google Scholar.[4] The Hoagland solution provides every essential nutrient required by green plants and is appropriate for supporting growth of a large variety of plant species.[5]
The solution described by Hoagland in 1933 has been modified several times, mainly to add ferric EDTAs and alter the number and concentrations of micronutrients. In the revision of 1950, only one concentration (Mo 0.01 ppm) was changed compared to 1938, while the concentration and composition of macronutrients remained the same since 1933. Accordingly, the original and the modified concentrations for each essential element are shown below, the calculation of these values being derived from Table (1).
- N 210 ppm
- K 235 ppm
- Ca 200 ppm
- P 31 ppm
- S 64 ppm
- Cl 0.65 ppm
- Na 1.2 ppm
- Mg 48.6 ppm
- B 0.5 ppm
- Fe 2.9 ppm
- Mn 0.5 ppm
- Zn 0.05 ppm
- Cu 0.02 ppm
- Mo 0.05 ppm
The Hoagland solution has high concentrations of N and K so it is very well suited for the development of large plants like tomato and bell pepper.[6] Due to relatively high concentrations in the stock solutions (Table (1)) the solution is very good for the growth of plants with lower nutrient demands as well, such as lettuce and aquatic plants, with the further dilution of the preparation to 1/4 or 1/5 of the modified solution.[7]
Salts and acids to make up the Hoagland hydroponic and soil culture solution formulations:
- Potassium nitrate, KNO3
- Calcium nitrate tetrahydrate, Ca(NO3)2•4H2O
- Magnesium sulfate heptahydrate, MgSO4•7H2O
- Potassium dihydrogen phosphate, KH2PO4 or
- Ammonium dihydrogen phosphate, (NH4)H2PO4
- Iron(III)-EDTA or Iron chelate, Fe-EDTA or Fe-EDDHA
- Boric acid, H3BO3
- Copper sulfate pentahydrate, CuSO4•5H2O
- Zinc sulfate heptahydrate, ZnSO4•7H2O
- Manganese chloride tetrahydrate, MnCl2•4H2O
- Molybdic acid monohydrate, H2MoO4•H2O or
- Sodium molybdate dihydrate, Na2MoO4•2H2O.
Table (1) to prepare the stock solutions and a full Hoagland solution (1):
| Component | Stock Solution | mL Stock Solution/1 L | |
|---|---|---|---|
| Macronutrients | |||
| 2M KNO3 | 202 g/L | 2.5 | |
| 2M Ca(NO3)2•4H2O | 236 g/0.5 L | 2.5 | |
| Iron (Sprint 138 iron chelate) | 15 g/L | 1.5 | |
| 2M MgSO4•7H2O | 493 g/L | 1 | |
| Micronutrients | |||
| H3BO3 | 2.86 g/L | 1 | |
| MnCl2•4H2O | 1.81 g/L | 1 | |
| ZnSO4•7H2O | 0.22 g/L | 1 | |
| CuSO4•5H2O | 0.08 g/L | 1 | |
| H2MoO4•H2O or | 0.09 g/L | 1 | |
| Na2MoO4•2H2O | 0.12 g/L | 1 | |
| Phosphate | |||
| 1M KH2PO4 | 136 g/L | 1 | |
The Hoagland solution formulation based on (NH4)H2PO4 instead of KH2PO4 must be prepared according to a different protocol, which is referred to in the circulars of 1938 and 1950 as solution (2). Sprint 138 iron chelate is produced as sodium Fe-EDDHA, while Hoagland's original solution formulation (1933) optionally contains ferric or ferrous tartrate but no sodium ions. Other micronutrients (e.g., Co, Ni) and rather non-essential elements (e.g., Pb, Hg) mentioned in Hoagland's 1933 original publication (known as A-Z solutions a and b[8]) are no longer included in his later circulars. These elements and organic compounds are not necessary for normal plant nutrition.[9] As an exception, there is evidence that, for example, some algae require cobalt for the synthesis of vitamin B12. On the other hand, it is evident that the modified Hoagland solutions of 1938 and beyond are balanced nutrient solutions that answer the question how to compose and concentrate the solutions best suited to the growth of plants.[10]
References
- Hoagland, D.R.; Snyder, W.C. (1933). "Nutrition of strawberry plant under controlled conditions. (a) Effects of deficiencies of boron and certain other elements, (b) susceptibility to injury from sodium salts". Proceedings of the American Society for Horticultural Science. 30: 288–294.
- Hoagland & Arnon (1938). The water-culture method for growing plants without soil (Circular (California Agricultural Experiment Station), 347. ed.). Berkeley, Calif. : University of California, College of Agriculture, Agricultural Experiment Station. OCLC 12406778.
- Hoagland & Arnon (1950). The water-culture method for growing plants without soil. (Circular (California Agricultural Experiment Station), 347. ed.). Berkeley, Calif. : University of California, College of Agriculture, Agricultural Experiment Station. (Revision). Retrieved 1 October 2014.
- "The water-culture method for growing plants without soil". Google Scholar. Retrieved 3 February 2020.
- Smith, G. S.; Johnston, C. M.; Cornforth, I. S. (1983). "Comparison of nutrient solutions for growth of plants in sand culture". The New Phytologist. 94 (4): 537–548. doi:10.1111/j.1469-8137.1983.tb04863.x. ISSN 1469-8137.
- He, F.; Thiele, B.; Watt, M.; Kraska, T.; Ulbrich, A.; Kuhn, A. J. (2019). "Effects of root cooling on plant growth and fruit quality of cocktail tomato during two consecutive seasons". Journal of Food Quality. Article ID 3598172: 1–15. doi:10.1155/2019/3598172.
- "The Hoaglands Solution for Hydroponic Cultivation". Science in Hydroponics. Retrieved 1 October 2014.
- Schropp, W.; Arenz, B. (1942). "Über die Wirkung der A‐Z‐Lösungen nach Hoagland und einiger ihrer Bestandteile auf das Pflanzenwachstum". Journal of Plant Nutrition and Soil Science. 26 (4–5): 198–246. doi:10.1002/jpln.19420260403.
- Murashige, T; Skoog, F (1962). "A revised medium for rapid growth and bio assays with tobacco tissue cultures". Physiologia Plantarum. 15 (3): 473–497. doi:10.1111/j.1399-3054.1962.tb08052.x.
- Hoagland, D.R. (1920). "Optimum nutrient solutions for plants". Science. 52 (1354): 562–564. Bibcode:1920Sci....52..562H. doi:10.1126/science.52.1354.562. PMID 17811355.