Elements needed for
Hydroponics it is essential that the plants are able to access all the
elements needed to grow and be healthy. These are the elements needed,
as well as a description of there functions to the plants. Carbon,
hydrogen and oxygen are absorbed from the air and water. The rest of
the elements, called mineral nutrients, are dissolved in the nutrient
(N) is primary to plant growth. Plants convert nitrogen to make
proteins essential to new cell growth. Nitrogen is mainly responsible
for leaf and stem growth as well as overall size and vigor. Nitrogen
moves easily to active young buds, shoots and leaves and slower to
older leaves. Deficiency signs show first in older leaves. They turn a
pale yellow and may die. New growth becomes weak and spindly. An
abundance of nitrogen will cause soft, weak growth and even delay
flower and fruit production if it is allowed to accumulate.
(P) is necessary for photosynthesis and works as a catalyst for energy
transfer within the plant. Phosphorus helps build strong roots and is
vital for flower and seed production. Highest levels of phosphorus are
used during germination, seedling growth and flowering. Deficiencies
will show in older leaves first. Leaves turn deep green on a uniformly
smaller, stunted plant. Leaves show brown or purple spots. NOTE:
Phosphorus flocculates when concentrated and combined with calcium.
(K) activates the manufacture and movement of sugars and starches, as
well as growth by cell division. Potassium increases chlorophyll in
foliage and helps regulate stomata openings so plants make better use
of light and air. Potassium encourages strong root growth, water uptake
and triggers enzymes that fight disease. Potassium is necessary during
all stages of growth. It is especially important in the development of
fruit. Deficiency signs of potassium are: plants are the tallest and
appear healthy. Older leaves mottle and yellow between veins, followed
by whole leaves that turn dark yellow and die. Flower and fruit drop
are common problems associated with potassium deficiency. Potassium is
usually locked out by high salinity.
(Mg) is found as a central atom in the chlorophyll molecule and is
essential to the absorption of light energy. Magnesium aids in the
utilization of nutrients, neutralizes acids and toxic compounds
produced by the plant. Deficiency signs of magnesium are: Older leaves
yellow from the center outward, while veins remain green on deficient
plants. Leaf tips and edges may discolor and curl upward. Growing tips
turn lime green if the deficiency progresses to the top of the plant.
(Ca) is fundamental to cell manufacture and growth. Soil gardeners use
dolomite lime, which contains calcium and magnesium, to keep the soil
sweet or buffered. Rockwool gardeners use calcium to buffer excess
nutrients. Calcium moves slowly within the plant and tends to
concentrate in roots and older growth. Consequently young growth shows
deficiency signs first. Deficient leaf tips, edges and new growth will
turn brown and die back. If too much calcium is applied early in life,
it will stunt growth as well. It will also flocculate when a
concentrated form is combined with potassium.
(S) is a component of plant proteins and plays a role in root growth
and chlorophyll supply. Distributed relatively evenly with largest
amounts in leaves which affects the flavor and odor in many plants.
Sulphur, like calcium, moves little within plant tissue and the first
signs of a deficiency are pale young leaves. Growth is slow but leaves
tend to get brittle and stay narrower than normal.
(Fe) is a key catalyst in chlorophyll production and is used in
photosynthesis. A lack of iron turns leaves pale yellow or white while
the veins remain green. Iron is difficult for plants to absorb and
moves slowly within the plant. Always use chelated (immediately
available to the plant) iron in nutrient mixes.
(Mg) works with plant enzymes to reduce nitrates before producing
proteins. A lack of manganese turns young leaves a mottled yellow or
(Z) is a catalyst and must be present in minute amounts for plant
growth. A lack of zinc results in stunting, yellowing and curling of
small leaves. An excess of zinc is uncommon but very toxic and causes
wilting or death.
(C) is a catalyst for several enzymes. A shortage of copper makes new
growth wilt and causes irregular growth. Excesses of copper causes
sudden death. Copper is also used as a fungicide and wards off insects
and diseases because of this property.
(B) is necessary for cells to divide and protein formation. It also
plays an active role in pollination and seed production.
(Mo) helps form proteins and aids the plant's ability to fix nitrogen
from the air. A deficiency causes leaves to turn pale and fringes to
appear scorched. Irregular leaf growth may also result.