“MOST soils supply
some of these ‘lesser’
nutrients, but very
often some are
missing. With other
grow media, these
nutrients will likely be
missing completely.”
from air and water
Carbon (C)
Hydrogen (H)
Oxygen (O)
from grow media and fertilizer
Primary:
Nitrogen (N)
Phosphorus (P)
Potassium (K)
Secondary:
Suphur (S)
Calcium (Ca)
Magnesium (Mg)
Zinc (Z)
Copper (Cu)
Iron (Fe)
Manganese (Mn)
Boron (B)
Chlorine (Cl)
Molybdenum (Mo)
Cobalt (Co)
Fig. 1
The idea of certain nutrients being more important than others is misleading.
Though the amount of these nutrients varies between plant genuses and species,
these nutrients are all required to some degree for plant health and vigor. As a crop’s
yield increases, so is the uptake of almost all essential nutrients. We can look at leaf
tissue analysis to get a better idea of how much of the essential nutrients a plant
actually needs. The chart below (Fig. 2) is reflective of a cereal crop similar to barley.
nutrient measured in per cent
low sufficient high
Nitrogen (N)
Phosphorous (P)
Potassium (K)
Sulfur (S)
Calcium (Ca)
Magnesium (Mg) 1.25
0.15
1.0
0.1
0.1
0.1 1.75 - 3.0
0.26 - 0.5
1.5 - 3.0
0.15 - 0.40
0.2 - 1.0
0.15 - 0.50 3.0 - 4.0
0.5 - 0.8
3.0 - 5.0
0.40 - 0.8
1.0 - 1.5
0.50 - 1.0
nutrient measured in PPM low sufficient high
Zinc (Zn)
Iron (Fe)
Manganese (Mn)
Chlorine (Cl)
Cobalt (Co)
Copper (Cu)
Boron (B)
Molybdenum (Mo) 10
15
10
3.0
1.7
2.3
3
0.01 15 - 70
20 - 250
15 - 100
4.5 - 25
2.5 - 25
3.7 - 25
5 - 25
0.03 - 5 70 - 150
250 - 500
100 - 250
25 - 50
25 - 50
25 - 50
25 - 70
5-10
Fig. 2 Plant Tissue Analysis - /Growth Stage Whole Plant
Note: Requirements for macronutrients is listed in per cent, while micronutrients
are ppm (or 1/10,000 per cent)
Source: Manitoba Provincial Soil Testing Laboratory, 1987.
grow cycle
109