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Understanding The Makeup Of Fertilizer – Part 2 – S, Ca, and Fe

At the top of almost all fertilizer labels, there is a list of the nutrients and their percentages. This is known as a “Guaranteed Analysis”. The guaranteed analysis is a legal claim of what % components make up each prill of the fertilizer contained within this bag. Refer to this list to determine if this is the right product for your crop

In this and the following series of blog posts, we will review these nutrients and share their roles in plant development.

This is part 2 of our 3 part series.

In this post, we will cover the following nutrients Sulfur (S), Calcium (Ca), and Iron (Fe).

Sulfur (S)

Sulfur (S) is considered the fourth most needed fertilizer nutrient after the three macronutrients nitrogen (N), phosphorus (P) and potassium (K). Sulfur (S) is key in the formation of chlorophyll, production of proteins, synthesis of oils, and activation of enzymes. Maintaining an adequate supply of S is essential for sustaining high-yielding crops.

Sulfur Deficiency Symptoms

Sulfur (S) deficiency symptoms consist of chlorosis (yellowing) and are first observed in the young tissues of leaves, stocks, and flower buds.

Calcium (Ca)

Calcium (Ca) nutrition plays a vital role in the production of high-quality crops. Calcium is classified as a “secondary nutrient” that is needed in relatively large amounts by plants in the form of Ca2+. In some species, the requirement for Ca is greater than for the macronutrient phosphorus (P).

Calcium plays a key role in cell wall structure and membrane integrity. Calcium also promotes proper plant cell elongation, participates in enzymatic and hormonal processes, and plays a role in the uptake processes of other nutrients.

Calcium Deficiency Symptoms

Symptoms of calcium deficiency first appear on younger leaves and tissues, growth is inhibited, and plants have a bushy appearance. The youngest leaves are usually small and misshapen with brown chlorotic spots developing along the margins, which spread to eventually unite in the center of the leaves.

- Parachute shaped leaves

- Death of root tips

- Chlorosis among the leaf margins

- Dark veins

- Weakened stems

Iron (Fe)

Iron (Fe) is a nutrient required by all organisms, including microbes, plants, animals, and humans. Iron is a component of many vital plant enzymes and is required for a wide range of biological functions. It is common in the earth’s crust and as a result, most soils contain abundant Fe, but in forms that are low in solubility and sometimes not readily available for plant uptake.

Iron Deficiency Symptoms

Iron (Fe) deficiency symptoms are universal among plant species, with general stunting and yellowing of younger leaves. Young Fe deficient leaves develop chlorosis (yellowing) between the leaf veins, while the veins initially remain green. As the deficiency becomes more severe, the younger leaves become pale yellow to white in color. The young tissue is impacted first because Fe is poorly mobile within plants and does not readily translocate from older to younger tissues.

Sources Used


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