Diagnosing Nutrient Deficiencies and Toxicities
Diagnose Nutrient Deficiencies
Many of the symptoms of nutrient deficiency are most easily detected (without special equipment and without damaging or digging up a plant) on the leaves of affected plants. The picture below can be used to help you diagnose a nutrient deficiency (if in doubt, a tissue test will confirm a plant nutrient deficiency and a soil test will help you determine whether a plant deficiency is due to too little nutrient in the soil, poor availability of the nutrient (as a result of a pH problem for instance) or a plant's inability to uptake sufficient nutrient). Clicking the picture will enable you to download a PDF that you can print or load onto a portable device for ease of reference.
Excess levels of a nutrient in the soil may lead to nutrient toxicity within a plant. Sometimes this will cause symptoms of toxicity and sometimes it will prevent a plant from being able to uptake enough of one or more other nutrients and thus will lead to symptoms of nutrient deficiency. The tables below show which excess nutrients may cause deficiencies in other nutrients as well as any additional symptoms of toxicity that may occur on top of symptoms of a deficiency.
Once you have identified a nutrient deficiency you may need to add some fertiliser to your soil. Usually, chemical symbols are used on fertiliser packaging so in order to determine whether a given fertiliser contains the nutrient you wish to boost, you need to know what the symbols mean. The table below will help you do just that.