The Importance of Plant Nutrition

Healthy plants spring from rich soil. Naturally fertile soils are found in other parts of the United States but most of the soil in SW Florida is made of sand, seasoned with lime rock, and peppered with shells. If it looks like it used to be the ocean floor, your are right. Plant growth and success is greatly influenced by the application of proper nutrients to our soil.

The amount of "data" and advice on plant nutrition is dizzying and often contradictory. This is a summary of various articles by experts on Florida plant nutrition that we hope will be easy to understand and provide great results.

The amount of salt that you put on your steak and how you like it done is strictly a matter of taste. But plants don't have opinions, they have needs. The following describes the nutritional needs of plants and how gardeners can provide them.

 

PALM NUTRITION

Palms are among the most important ornamental plants in Florida landscapes. Palms suffer quickly and conspicuously from improper mineral nutrition, whether due to insufficient or incorrect fertilization. They also may exhibit certain nutritional disorders in unique ways compared to other ornamental plants. You can slowly kill large, valuable palms by applying the wrong fertilizer (or no fertilizer at all.)

Sixteen plant food nutrients are essential for proper plant development.  Each is equally important to the plant yet, each is required in vastly different amounts.  These differences have led to the grouping of these essential elements into three categories. 

 

PRIMARY (MACRO) ELEMENTS

Primary (macro) elements are nitrogen, phosphorus and Potassium.  They are the most frequently required in a plant fertilization program.  They are also needed in the greatest total quantity by plants as fertilizer.

 

NITROGEN (N)

*Necessary for formation of amino acids, the building blocks of protein 

*Essential for plant cell division, vital for plant growth

*Directly involved in photosynthesis

*Necessary component of vitamins

*Aids in the production and use of carbohydrates

*Affects energy reactions in the plant

 

PHOSPHORUS (P)

*Involved in photosynthesis, respiration, energy storage, transfer cell division, and enlargement

*Promotes early root formation and growth

*Improves quality of fruits and vegetables

*Vital to seed formation

*Helps plants survive harsh winter conditions

*Increases water-use efficiency

*Hastens maturity

 

POTASSIUM (K)

*Carbohydrate metabolism and the break down and translocation of starches.

*Increases photosynthesis

*Increases water-use efficiency

*Work "behind-the-scene" as activators of many plant functions

*Essential to protein synthesis

*Important in fruit formation

*Activates enzymes and controls their reaction rates

*Improves quality of seeds and fruit

*Improves winter hardiness

*Increases disease resistance

 

SECONDARY NUTRIENTS

The secondary nutrients are calcium, magnesium, and sulphur.  For most plants, these three are needed in lesser amounts than the primary nutrients.  They are growing in importance in plant fertilization programs due to more stringent clear air standards and efforts to improve the environment.

 

CALCIUM (Cl)

*Utilized for continuous cell division and formation

*Involved in nitrogen metabolism

*Reduces plant respiration

*Aids translocation of photosynthesis from leaves to fruiting organs

*Increases fruit set

*Stimulates microbial activity

 

MAGNESIUM (Mg)

*Key element chlorophyll production

*Improves utilization and mobility of phosphorus

*Activator and componenet of many plant enzymes

*Increases iron utilization in plants

*Influences earliness and uniformity of maturity

 

SULFUR (S)

*Integral part of amino acids

*Helps develop enzymes and vitamins

*Aids in seed production

*Necesary in chlorophyll formation

 

*MICRONUTRIENTS

The micronutrients are Boron, chlorine, copper, iron, manganese, molybdenium, and zinc.  These plant food elements are used in very small amounts, but they are just as important to plant development as the major nutrients.  Especially, their "work behind the scenes" as activators of many plant functions.

 

BORON (B)

*Essential germination of pollen grains and growth of pollen tubes

*Essential for seed and cell wall formation

*Promotes maturity

*Nucessary for sugar translocation

*Affects nitrogen and carbohydrates

 

CHLORINE (Cl)

*Total functions in plant nutrition still not known

*Interferes with P uptake

 

COPPER (Ca)

*Catalyzes several different plant processes

*Major function in photosynthesis

*Major function in reproductive stages

*Indirect role in chlorophyll production

*Influences sugar content

*Intensifies color

*Improves flavor of fruits and vegetables

 

 IRON (Fe)

*Promotes formation of clorophyll

*Acts as an oxygen carrier

*Reactions involving cell division and vegetables

 

MANGANESE (Ma) 

*Functions as a part of certain enzyme systems

*Aids in chlorophyll synthesis

*Increases the availablility of P and CA

 

MOLYDDENUM (Mo)

*Required to form the enzyme "nitrate reductus" which reduces nitrates to ammonium.

*Aids in the formation of legumes

*Needed to convert inorganic phosphates to organic forms in the plant.

 

ZINC (Zn)

*Aids plant growth hormones and enzyme systems

*Necessary for chlorophyll, carbohydrate and starch formation

*Aids in seed formation

In addition to the 13 nutrients listed above, plants require carbon(C), hydrogen(H), and oxygen(O), which are extracted from air and water to make up the bulk of plant weight.

 

References:

Soil pH and Plants: http://edis.ifas.ufl.edu/MG092

The Florida Fertilizer Label: http://edis.ifas.ufl.edu/LH014

Fertilization of Field-grown and Landscape Palms in Florida: http://edis.ifas.ufl.edu/ed261

Palm Nutrition Guids: http://www.floridaplants.com/horticulture/palm.htm

South Florida Horticulture: http://southfloridahorticulture.com/v2/fertilization

Palm Nutrition Guide: http://edis.ifas.ufl.edu.ss-orh-02

Soil pH and the Home Landscape or Garden: http://edis.ifas.ufl.edu/ss480

Bob Cook, FNGLA Instructor

 

 

 

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