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Understanding Plant Nutrition

Eighteen elements are considered essential for plant growth. Carbon, hydrogen, and oxygen are primarily supplied by air and water. Plant roots absorb the remaining 15 elements from the surrounding soil. These elements are divided into three groups based on their relative abundance in plants: Primary Nutrients (or Major Nutrients), Secondary Nutrients (or Minor Nutrients), and Trace Nutrients (or Micronutrients). Although the Major Nutrients are needed in the greatest quantities, a deficiency of any one nutrient can prevent plant growth, or reduce it to unsatisfactory levels. Even though some soils may already contain these nutrients, they may not be in a form available for plant growth. The best way to ensure that all of the nutrients are available in the soil is through regular applications of plant foods. Table 1 provides more information on each nutrient, its deficiency symptoms, and possible plant foods to cure the deficiency.
PrimaryNutrients Function Deficiency Symptoms *Solutions


Vigorous growth & dark greencolor

Light green leaves; stuntedgrowth

Dried Blood, Garden Manure, Cottonseed Meal,Ammonium Sulfate, Urea


Root development &flowering

Smaller yields of seeds & fruit; purplishleaves, stems & branches;

Rock Phosphate, Bone Meal, SingleSuperphosphate, Triple Superphosphate


Overall hardiness & diseaseresistance

Reduced yields; Spotted or curled leaves;Weak root system

Sulfate of Potash, Sulfate of PotashMagnesia, Muriate of Potash, Greensand

SecondaryNutrients Function DeficiencySymptoms *Solutions


Plant vigor; Aids in uptake of nutrients

Deformed terminal leaves; Poor root growth

Garden Lime, Garden Gypsum


Essential part of chlorophyll

Yellowing of older leaves

Garden Lime, Sulfate of Potash Magnesia


Dark green color; Seed production

Yellow leaves; Stunted, spindly plants

Garden Sulfur, Sulfate of Potash, Gypsum

TraceNutrients Function DeficiencySymptoms *Solutions


Increases flowering & fruit development

Terminal buds die; Less flowers & fruit develop

Garden Manure, Bone Meal


Helps control water loss & moisture stress

Plants wilt; yellow leaves

Muriate of Potash, Garden Manure, Greensand


Improves growth & transpiration

Reduced growth and yellowing of foliage

Greensand, Kelp, Cottonseed Meal


Helps produce chlorophyll

Yellow, wilted leaves; Lack of flowering

Garden Manure, Greensand


Promotes dark green leaves

Yellow leaves

Greensand, Garden Manure, Cottonseed Meal


Helps produce chlorophyll

Intervenous chlorosis in younger leaves

Garden Manure, Greensand


Essential in some enzyme systems

Pale green, rolled or cupped leaves

Greensand, Lime (makes it more available)


Aids water regulation & photosynthesis

Plants wilt

Kelp, Garden Manure, Bone Meal, Greensand


Enzyme & growth hormone production

Yellow leaves, Rosetted (clustered) leaves

Garden Manure, Greensand, Cottonseed Meal

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