Download macronutrients

MACRONUTRIENTS
Fertilizers are identified by their percentages of their main active ingredients,
illustrated by a three number formula such as 14-14-14, 18-6-12, or 22-8-2.
These numbers represent the percentage of nitrogen, phosphorus, and
potassium which are in the fertilizer. These three ingredients are often referred
to by their chemical abbreviations, which are N-P-K. These three elements are
called ‘macronutrients’, and plants use these in greater quantity than any other
element. (see also micronutrients)
N stands for nitrogen
P stands for phosphorus
K stands for potassium
N-P-K is always listed in this order. For example, a fertilizer that is listed in our
catalog or on our website as 14-25-10 is:
14% nitrogen (N)
25% phosphorus (P)
10% potassium (K)
If you add the 14% N plus the 25% P plus the 10% K you get 49%. This means
that the other 51% contained in the bag of fertilizer is either coatings to keep the
fertilizer from being released to the plant too quickly, or carriers to help the
fertilizer spread more evenly. If the N-P-K totaled 100% of the fertilizer, you
would be spreading the material so lightly that it would be hard to fertilize an area
evenly.
Nitrogen is associated with plant growth above the ground. Young buds, shoots
and leaves use it extensively. Nitrogen is easily washed away and must be
replaced regularly, especially during vegetative growth, however excess levels of
nitrogen can cause burning of the leaves and roots. Lack of nitrogen is the most
common nutrient deficiency. Symptoms include slower or stunted growth, and
older, lower leaves that don’t product enough chlorophyll so they become pale or
yellow. If the deficiency is not corrected, the yellowing progressively moves to
younger leaves.
Phosphorous is necessary for photosynthesis, and is associated with the overall
vigor of a plant, as well as flower and fruit production. Symptoms of
phosphorous deficiency are similar to nitrogen deficiency, but plants that require
phosphorous may also have reddish, purple stems and delayed fruit and flower
development.
Potassium is used at all stages of growth. Potassium promotes disease
resistance, water intake, and strong root growth. It is essential to the
manufacture, accumulation and movement of carbohydrates, as well as growth
by cell division. Deficiencies are difficult to detect, but are indicated by leaf
edges and tips that yellow then brown, flowering is retarded and diminished,
leaves curl up and older leaves drop off, and by weak stems.