Hoagland's solution (HS) is a hydroponic nutrient solution developed by Hoagland and Snyder in 1933. Modified by Hoagland and Arnon in 1938, and revised again by Arnon in 1950.
It is one of the most popular standard solution compositions for growing plants in the scientific world at least with more than 21,000 citations from Google Scholar - which is not necessarily a quality aspect, see iron content of spinach.
Hoagland's solution provides all the essential elements for plant nutrition and is suitable for supporting normal growth of a wide variety of plant species. The artificial solution described by Dennis Hoagland in 1933, known as Hoagland's solution, has been modified several times, primarily by adding iron chelates and other trace elements.
In Hoagland's 1938 nutrient recipes, known as Hoagland Solutions (1 and 2), the number of trace elements was subsequently reduced to the generally recognized essential elements (B, Mn, Zn, Cu, Mo, Fe, and Cl). Later studies confirmed that their concentrations had been adjusted for optimal plant growth.
In Arnon's 1950 revision, only one concentration (Mo 0.011 ppm) was changed compared to 1938 (Mo 0.048 ppm), while the concentration of macronutrients of Hoagland solutions (0), (1), and (2) remained the same since 1933, with the exception of calcium (160 ppm) in solution. The main difference between solution (1) and solution (2) is the different use of nitrate nitrogen and the ammonium nitrogen base.
Composition and concentrations of macronutrients
in Hoagland's solutions (0, 1, 2) and in Knop's solution
| Macronutrients | Hoagland's solution 0 and 1 | Hoagland's Solution 2 | Knops solution |
| Amount in the solution | |||
| μmol/L | μmol/L | μmol/L | |
| K+ | 6,000 | 6,000 | 4,310 |
| Ca2+ | 5,000* | 4,000** | 6,094 |
| Mg2+ | 2,000 | 2,000 | 1,014 |
| NO3 − | 15,000 | 14,000 | 14,661 |
| NH4+ | - | 1,000 | - |
| SO42− | 2,000 | 2,000 | 1,014 |
| PO43− | 1,000 | 1,000 | 1,837 |
Applications:
Plant nutrients are normally absorbed into the soil solution. Hoagland's solution, originally designed to mimic a (nutrient-rich) soil solution, has high concentrations of N and K, making it ideal for developing large plants such as tomatoes and peppers.
Components
Salts, acids and complex ions are used to prepare Hoagland hydroponic solution formulations (1) and (2).
- 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
Boric acid, H.3BO3
Manganese chloride tetrahydrate, MnCl2• 4H2O.
Zinc sulfate heptahydrate, ZnsO4• 7H2O.
Copper sulfate pentahydrate, CuSO4• 5H2O.
Molybdic acid monohydrate, H.2MoO4•H2O or
Sodium molybdate dihydrate, Na2MoO4• 2H2O.
Ferrous tartrate or iron(III)-EDTA− or iron chelate (Fe-EDDHA−)
Components for Hoagland Solution 1
To prepare the stock solutions and obtain a complete Hoagland solution, here are the ingredients:
Table 1
| Component | Amounts in solution | |
|---|---|---|
| g / l | ml / l | |
| Macronutrients | ||
| 2M KNO3 | 202 | 2.5 |
| 2M Ca (NO3)2• 4H2O. | 472 | 2.5 |
| 2M MgSO4• 7H2O. | 493 | 1 |
| 1M KH2PO4 | 136 | 1 |
| Micronutrients | ||
| H3 BO3 | 2.86 | 1 |
| MnCl2 • 4H2O | 1.81 | 1 |
| ZnsO4 • 7H2O | 0.22 | 1 |
| CuSO4 • 5H2O | 0.08 | 1 |
| H2MoO4 •H2O or | 0.09 | 1 |
| Na2MoO4 • 2H2O | 0.12 | 1 |
| iron | ||
| C12H12Fe2O18 or Sprint 138 iron chelate* * |
5 15 |
1 1.5 |
Components for Hoagland Solution 2
To prepare the stock solutions and obtain a complete Hoagland solution, here are the ingredients:
Table 2
| component | Amounts in solution | |
|---|---|---|
| g / l | ml / l | |
| Macronutrients | ||
| 2M KNO 3 | 202 | 3 |
| 2M Ca (NO3)2• 4H2O. | 472 | 2 |
| 2M MgSO4• 7H2O. | 493 | 1 |
| 1M NH4H.2PO4 | 115 | 1 |
| Micronutrients | ||
| H3BO3 | 2.86 | 1 |
| MnCl2• 4H2O | 1.81 | 1 |
| ZnsO4• 7H2O | 0.22 | 1 |
| CuSO4• 5H2O | 0.08 | 1 |
| H2MoO4•H2O. | 0.02 | 1 |
| iron | ||
|
C12H12Fe2O18, or Sprint 138 Iron Chelate * |
5 15 |
1 1.5 |
Trace element supplement according to DR Hoagland
- One liter of prepared Hoagland solution (supplemental nutrient solution, solution A) contains:
55 mg Al 2 (SO 4 ) 2
28 mg KJ
28 mg KBr
55 mg TiO 2
28 mg SnCl 2 · 2 H 2 O
28 mg LiCl
389 mg MnCl 2 · 4 H 2 O
614 mg B(OH) 3
55 mg ZnSO 4
55 mg CuSO 4 · 5 H 2 O
59 mg NiSO 4 · 7 H 2 O
55 mg Co(NO 3 ) 2 · 6 H 2 O
Source among others: https://en.wikipedia.org/wiki/Hoagland_solution
Image: Dennis Robert Hoagland - Smithsonian Libraries and Archives, Public Domain, https://commons.wikimedia.org/w/index.php?curid=159882668
ID: 717
Context: