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Three Important Nutrient Imbalance Terms


Chlorosis occurs when there isn't enough chlorophyll in a leaf. Chlorophyll is the green chemical that enables plants to produce sugars so when there isn't enough chlorophyll in a leaf, it turns yellow.


Necrosis is the term given to dead plant tissue. Necrotic tissue, which may be on leaves or other parts of the plant, will appear brown and after some time, will dry up.


Interveinal means 'between the veins'. On this website you may see the term 'interveinal chlorosis' and this means yellowing between the veins of a leaf. 'Interveinal necrosis' means that there are dead patches between the leaf veins.

Other Useful Terms


A positively charged element or combination of elements. In the soil cations include:


A negatively charged element or combination of elements. In the soil anions include:


Macronutrients are those nutrients that are required in large amounts by plants to complete their normal life cycle and/or because they are part of an essential part of the plant (or an essential compound that the plant makes).

Structural Macronutrients

Carbon (C), hydrogen (H) and oxygen (O) are the nutrients used in the physical structure of plants and are thus called structural macronutrients.

Primary Macronutrient

Primary macronutrients are heavily used by plants, are required for them to grow and are most likely to be added to the soil in fertilisers because deficiencies in these nutrients are likely to limit the yield of plants. All may be leached from the soil fairly easily as well. The three primary macronutrients are nitrogen (N), phosphorus (P) and potassium (K).

Secondary Macronutrient

A deficiency in any of the secondary macronutrients is less likely to occur because slightly lower amounts are required by most plants when compared with the primary macronutrients but these nutrients are nevertheless required by plants in fairly large amounts. The secondary macronutrients are calcium (Ca), magnesium (Mg) and sulfur (S).


Micronutrients are those elements essential for plant growth which are required in only very small amounts. They may also be referred to as trace elements. The commonly recognised micronutrients are boron (B), copper (Cu), iron (Fe), chlorine (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn). Nickel (Ni) has only been recognised as a micronutrient relatively recently and its status as an essential nutrient is still contested by some.

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