Application of Fertilizers


Historical Information
  Determination of Essentiality
Function in Plants
  Metabolic Processes
  Fruit Yield and Quality
Diagnosis of Magnesium Status in Plants
  Symptoms of Deficiency and Excess
    - Symptoms of Deficiency
    - Symptoms of Excess
  Environmental Causes of Deficiency Symptoms
  Nutrient Imbalances and Symptoms of Deficiency
    - Potassium and Magnesium
    - Calcium and Magnesium
    - Nitrogen and Magnesium
    - Sodium and Magnesium
    - Iron and Magnesium
    - Manganese and Magnesium
    - Zinc and Magnesium
    - Phosphorus and Magnesium
    - Copper and Magnesium
    - Chloride and Magnesium
    - Aluminum and Magnesium
  Phenotypic Differences in Accumulation
  Genotypic Differences in Accumulation
Concentrations of Magnesium in Plants
  Magnesium Constituents
    - Distribution in Plants
    - Seasonal Variations
    - Physiological Aspects of Magnesium Allocation
  Critical Concentrations
    - Tissue Magnesium Concentration Associations with Crop Yields
    - Tabulated Data of Concentrations by Crops
Assessment of Magnesium in Soils
  Forms of Magnesium in Soils
  Sodium Absorption Ratio
  Soil Tests
  Tabulated Data on Magnesium Contents in Soils
    - Soil Types
Fertilizers for Magnesium
  Kinds of Fertilizers
  Effects of Fertilizers on Plant Growth
  Application of Fertilizers
The primary goal is to have sufficient magnesium, relative to other nutrients, readily available for plant uptake throughout crop development. The type and rate of magnesium to apply depends upon the crop, soil type, and method of production (field, container, or hydroponics). If plants are grown hydroponically, a completely soluble form of magnesium would be required. For container-grown nursery crops, Whitcomb (119,120) suggested injecting dissolved Epsom salts (magnesium sulfate) into irrigation water at a rate to produce a calcium/magnesium ratio from 1:1 up to 5:1. In preliminary studies with juniper (Juniperus spp. L.), increased vegetative growth occurred when magnesium was supplied by applications of magnesium sulfate in the irrigation water versus equivalent magnesium applications through the incorporation of fine dolomitic lime into the planting media (119-121). Obatolu (226) reported that magnesium deficiency resulted in a loss of yield and quality of tea (Camellia sinensis O. Kuntze) in Nigerian plantations. A spray of 30% magnesium oxide corrected magnesium deficiency within 14 days and increased growth from 16 to 134%. Two applications of a 20% solution were required to correct deficiencies. A second application of the 30% solution was toxic to the tea plants.