Scientists do not consider selenium to be an essential plant nutrient. However, it is beneficial because it helps plants resist stressors.
Potassium ions are found in every living cell, probably because they are necessary to activate enzymes controlling so many crucial processes.
Phosphorus is associated with fruit production in the minds of gardeners because it is the most important element for germination and growth.
Because plants contain so much nitrogen, it is little wonder that they require ample amounts. Without it, plants simply cannot grow.
Until recently, scientists did not consider nickel essential for plant growth. Now nickel is recognized as an essential nanonutrient.
Manganese is an important micronutrient. It helps to activate some of the key enzyme systems in plants. But it has many other roles, too.
K-State has an excellent collection of gardening resources on a wide range of topics available as free PDF downloads.
Magnesium serves two roles affecting plants. One is improving plant health via the soil, and the other is improving plant health directly.
Did you know that plants need iron? No iron, no chlorophyll, and therefore no photosynthesis.
Copper is of particular importance to cereal crops because of its role in reproductive growth and grain production.