Nutri-Facts - North America

A series of fact sheets written by scientific staff of the International Plant Nutrition Institute (IPNI) that is focused on essential plant nutrients and their use.



Selenium (Se) is not essential for plants, but is required for many physiological functions in humans and animals. Since Se is obtained primarily from food, it’s accumulation by plants impacts human health.

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Silicon (Si) is generally not considered an essential element for plant growth. However, due to its important role in plant nutrition, particularly under stressful conditions, it is now recognized as a “beneficial substance” or “quasi-essential.”

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In crop production, sulfur (S) is used by plants in sufficient quantities that it is considered the fourth most needed fertilizer nutrient after the three macronutrients nitrogen (N), phosphorus (P) and potassium (K). Sulfur fertilization is increasingly common because higher yielding crops are taking up and removing more S from soil as harvested products. Due to a decrease in S emissions from industrial and transportation sources, S deposition from the atmosphere is much lower than a few decades ago. Maintaining an adequate supply of S is essential for sustaining high-yielding crops, as well as for animal and human nutrition.

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