Nutrient Solutions - Foundation for the Development of Controlled

Nutrient Solutions
for Controlled Environment Agriculture
Presented by
Dr. Don C. Wilkerson, Professor & Extension Specialist (Emeritus)
Department of Horticultural Sciences
Texas A&M University College Station, Texas
Caliber Biotheraputics, College Station, Texas
Baron Justus von Liebig
Darmstadt Germany
May 12, 1803
German scientist in the mid-19th century, showed that
nutrients are essential for plant life.
He stated, "We have determined that a number of elements
are absolutely essential to plant life. They are essential
because a plant deprived of any one of these elements would
cease to exist.
16 - Essential Plant Nutrients:
C, H, O,
N, P, K,
Macro Nutrients
Ca, S, Mg, Secondary Nutrients
Fe, Zn, Mn, Cu, B, Mo,
Cl
Micro Nutrients
“They are essential because a plant deprived of
any one of these elements would cease to exist. “
Substrate Plant Nutrition
Versus
Hydroponic Plant Nutrition
Substrate Plant Nutrition:
Measured as Cation Exchange Capacity (CEC)
Hydroponic Plant Nutrition:
Plant nutrients in the bulk solution.
Substrates (i.e. rockwool) primarily for anchorage.
Developing a
Hydroponic Nutrient Solution
• More Cost Efficient
• More Precise Control of Plant Nutrition
• Eliminates Substrates as Potential Source of
Contamination
Hoagland Solution
The Hoagland solution is a hydroponic nutrient solution
released by Hoagland and Arnon in 1938 and revised by
Arnon in 1950. This solution is was among the first
developed for growing plants without soil/substrate.
Dennis Robert Hoagland (1884-1949)
Daniel I. Arnon (1910 - 1994)
The Hoagland solution provides all of the essential
nutrients for plant growth and is appropriate for a wide
range of plant species. The solution described by
Hoagland and Arnon in 1950 has been modified several
times, mainly to add iron chelates for improved stability.
Basic Hoagland Solution:
Component
Stock Solution
mL Stock Solution/1L
Macronutrients
2M KNO3
202 g/L
2.5
1M Ca(NO3)2•4H2O
236 g/0.5L
2.5
Iron (Sprint 138 iron
chelate)
15 g/L
1.5
2M MgSO4•7H2O
493 g/L
1
1M NH4NO3
80 g/L
1
H3BO3
2.86 g/L
1
MnCl2•4H2O
1.81 g/L
1
ZnSO4•7H2O
0.22 g/L
1
CuSO4•5H2O
0.051 g/L
1
H3MoO4•H2O or
0.09 g/L
1
Na2MoO4•2H2O
0.12 g/L
1
136 g/L
0.5
Micronutrients
Phosphate
1M KH2PO4 (pH to 6.0)
N 210 ppm
K 235 ppm
Ca 200 ppm
P 31 ppm
S 64 ppm
Mg 48 ppm
B 0.5 ppm
Fe 1 to 5 ppm
Mn 0.5 ppm
Zn 0.05 ppm
Cu 0.02 ppm
Mo 0.01 ppm
Nutrient Solution Optimization
Knowing the nutrients required to grow plants hydroponically is
only one aspect of successful crop production. Maximizing yield
also requires additional optimization of the solution.
• Concentration to apply (ppm or EC)
• Timing of application (stage/rate of
growth)
• Source of nutrients to use
• Water quality
• Solution temperature
• Environmental conditions
(temperature/humidity)
• Light
• Carbon Dioxide levels
Nutrient Solution Optimization
Continued…
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pH (5.5 – 6.5)
Buffer Capacity
Electrical Conductivity (salinity)
Temperature
UV Light
Availability/Solubility (Precipitation)
Concentrates (1:200)
Pre-Mixed vs Make Your Own