- One of the 13 essential elements for plant growth and is one of the 6 Major Elements, based on concentration required
- Sulfur is essential to good flavor in vegetables
- principle form of uptake: ionic form sulfate (SO42-)
- amount required for healthy plant growth: 1,000 ppm, 0.1%, dry soil matter
- application of about 20 lbs sulfur per acre is generally adequate to ensure that sulfur is not limiting for vegetable production
- soil conditions related to deficiency of sulfur:
- sandy or mineral soils low in organic matter
- soils after years of cropping
- acid soils subjected to high rainfall
- soils formed from low-sulfur parent material
- no substantial deposition of sulfur by acid rain
- use of low-sulfur N-P-K fertilizers (like triple superphosphate)
- sulfur moves through the soil primarily via diffusion
- soil factors that affect uptake of sulfur by plants:
- soil levels
- temperature
- the level of decomposition of organic matter
- plant factors that affect uptake:
- hybrid or variety of plant
- stage of growth
- interaction with other elements
- functions of sulfur in plant:
- this nutrient forms organic compounds in the plant that gives flavor to vegetables
- reduces the incidence of disease in many plants
- combines with carbohydrates to form amino acids & proteins used in enzymatic processes
- involved in protein synthesis
- part of amino acids cystine and thiamine
- present in peptide glutathione, coenzyme A, vitamin B1, glucosides (such as mustard oil and thiols that contribute to the characteristic odor and taste of plants in the Cruciferae and Liliaceae families)
Sources for Sulfur:
- organic debris, plant residues, and microorganisms are the major sources of sulfur
- compost
- gypsum
- potassium sulfate
- potassium magnesium sulfate
Sulfur Deficiency Symptoms:
- pale yellow-green leaves (can be confused with nitrogen deficiency)