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Calcium: Top 5 Things You Need to Know

Calcium deficiency

While some may call it a “secondary nutrient,” there’s no denying the importance of calcium for crop health. It quite literally holds the crop together (well, the cell walls at least). Calcium is essential for plant tissue strength and development, enzyme activation and communicating signals to coordinate cellular functions. Here are five things to remember when it comes to calcium.

1. Calcium is not highly mobile in plants

Calcium can not move freely within plants. It can only travel upwards (a.k.a. xylem mobility), and once in place, it can’t remobilize and move to new developing tissues. Because of this, even if the soil surrounding the roots has high calcium concentrations, the individual plants may not have enough—or not in the right places. This causes signs of calcium deficiency to be slow to appear and primarily found in young leaves. Some additional nutrients with similar limitations in mobility include boron, manganese, sulfur and zinc.

2. Calcium determines cell wall rigidity

Higher calcium concentrations = stronger cell walls. It’s just that simple. Calcium goes through cycles of varying concentrations within cells to allow necessary functions to carry out. For example, calcium needs to decrease to allow the cell walls to weaken enough for expansion during growth, while calcium increases in response to stress, from factors such as foreign pathogens, to create a strong barrier against these harmful infections.

3. Calcium is a cellular messenger

While calcium is a key component in cell structure, it’s also essential for communication and cell functionality. Changes in the ionic calcium concentrations create chain reactions within cells, being the ringmaster for functions such as root growth and stress responses. Calcium senses the change in the environment or within the plant, which creates a signal that is decoded into a plan of action by cell components downstream.

4. Calcium deficiency impacts plant roots

When a plant is lacking calcium, its roots suffer—from halted growth to root tips dying. Because calcium is immobile and the effects are most concentrated in the roots, it can take a while to see visual cues of calcium deficiency. Once the roots experience these symptoms of impacted growth and dying root tips, the effects will work their way up the plant. New, young leaves on the crop will appear distorted, curled or resemble a hook. The tips of the leaves may also further shrivel up and die.

5. Tissue sampling identifies calcium deficiency earliest

Because signs of calcium deficiency can take a while to become noticeable on plant leaves, tissue sampling is the best way to identify potential nutrient deficiencies early. This early identification may be a critical factor in the overall crop performance. By the time you see visual signs of calcium deficiency, the crop’s maximum yield potential has lowered.

Being clear on specific nutrient levels and how they vary across your fields allows you to properly treat deficiencies and provide supplemental nutrition to your plants—where they need it. Agronomy 365’s thorough in-season soil and tissue sampling program gives you the insights you need to monitor levels of calcium—and all other essential nutrients—throughout each zone in your fields. It’s important to test tissue along with soil, as calcium’s lack of mobility means even if the soil is sufficient in calcium, the plant may not be.

P.S. If you’ve got fields that just can’t get enough calcium, we have the solution for you. BW-HumiCal can be applied in the fall (a perfect pairing for BW-Meltdown) to give your spring crops the calcium they need to start the season strong now, rather than having to treat yield-lowering deficiencies later.