Understanding and Managing Calcium (Ca) Deficiency

Calcium—it’s essential to recognize the significant impact of calcium deficiency on agricultural yields. Here, we’ll explore the effects of calcium deficiency on various crops, identify common signs of deficiency, discuss proactive measures to prevent deficiencies, and outline strategies to remedy it when it occurs.

What is a calcium deficiency?

A calcium deficiency means there is insufficient calcium in the soil or inadequate uptake by plants. This deficiency can often lead to physiological impairments, like cell deterioration, tissue collapse, and reduced nutrient uptake, which can impact plant vigor and disease resistance. Calcium deficiency usually results in reduced crop quality.

Why is calcium so important for crops?

Calcium is essential for plant cell division, strengthening cell walls, and improving nutrient absorption, contributing to overall plant growth and health. Calcium might be considered a secondary macronutrient, but it’s essential for the overall productivity of crops! It influences various physiological processes critical for plant performance (like cell wall structure and nutrient transport) and improves crop resilience in agricultural ecosystems. Secondary macronutrients, like calcium, also work in synergy with phosphorus, potassium, and nitrogen, so ensuring a balanced supply of nutrients is good for managing calcium deficiency and optimizing nutrient efficiency.

What are the common signs and symptoms of calcium deficiency?

Calcium deficiency shows up in different ways but commonly can lead to various symptoms such as:

• Leaf Tip Burn: Necrosis or browning of leaf tips, often progressing inward along leaf margins.
• Leaf Curling: Upward or inward curling of young leaves, accompanied by distortion or stunted growth.
• Blossom End Rot: Sunken, darkened lesions on the blossom end of fruits, such as tomatoes, peppers, and watermelons.
• Fruit Cracking: Cracks or fissures on the surface of fruits, particularly in tomatoes, apples, and peppers.
• Stunted Root Growth & Tip Necrosis: Reduced root development, browning, or blackening of root tips, indicating impaired root function and poor nutrient absorption.
• Weak Stems: Weak, brittle stems prone to lodging or breaking, particularly in cereals like wheat and corn.

How does calcium deficiency impact yield?

Calcium deficiency in crops can lead to a higher risk of disease, decreased ability to handle stress, and a lower quality of crops. These crops may also become more sensitive to environmental stressors such as drought, heat, and salinity. It is essential to address calcium deficiency through proper soil management and fertilization practices. Not only will it help to optimize crop performance, it will also ensure sustainable agricultural production.

How does calcium affect specific crops?

Crop-Specific Effects of Calcium Deficiency:

Potatoes:

• Increased risk of internal rust spot (internal browning) and hollow heart.
• Reduced tuber quality and marketability.
• Increased risk of tuber disorders and lack of structural integrity

Apples:

• Higher incidence of bitter pit and cork spot.
• Decreased fruit quality and shelf life.

Soybeans:

• Greater susceptibility to diseases like soybean cyst nematode and sudden death syndrome.
• Decreased seed quality and oil content.

Corn:

• Increased likelihood of blossom end rot.
• Reduced kernel development and grain quality.

Almonds:

• Higher incidence of bitter pit and shell breakdown.
• Decreased nut quality and size.

Cotton:

• Increased risk of leaf curl and boll rot.
• Decreased fiber quality and yield.

How can growers avoid calcium deficiency?

• Regular soil testing and analysis should be conducted to assess calcium levels and pH.
• Incorporate calcium-rich soil amendments, like Polysulphate^® that provides a sustained release of calcium that matches crop uptake.
• Take a balanced approach to fertilization practices and incorporate calcium applications into soil and foliar applications to adjust to crops’ needs and environmental conditions.
• Implement crop rotation, diversification, and precision agriculture technologies.
• Manage water and organic matter effectively to enhance soil calcium availability.

Remedies for Calcium Deficiency:

• Calcium-containing fertilizers, such as Polysulphate, Agrolution pHLow^® High K Plus Ca, and Agrolution High^® K CalMag 11-6-20 +6Ca +1.5Mg, can be applied through soil or foliar applications.
• Standard practices include adding gypsum or lime to raise soil calcium levels and adjust pH. However, using gradual-release multi-nutrients like Polysulphate or addressing pH and calcium levels with an acidifying fertigation and pH management solution like Nova^® PeKacid or Agrolution pHLow^® can often yield optimal results with a better economic and environmental return.
• Address underlying soil factors affecting calcium availability, such as compaction or excessive leaching.

Why is Polysulphate (polyhalite) an excellent source of calcium?

• Polysulphate contains 12.2% soluble calcium sulfate, making it a valuable source of calcium for plants.
• Polysulphate provides a gradual release of calcium, maintaining essential soil reserves and balancing cation exchange capacity, which is particularly beneficial for acidic soils.
• Calcium from Polysulphate helps alleviate aluminum toxicity symptoms and counteracts challenges like sodium, aluminum, and bicarbonate in soil, promoting soil health and fertility.

How does managing pH help with calcium?

Soil pH directly affects the availability and uptake of calcium by plants!

• Optimal soil pH (typically between 6.0 and 7.5) maximizes calcium availability to plants.
• Maintaining proper pH improves soil structure, aiding root growth and nutrient uptake, including calcium.
• Soil pH management ensures calcium remains soluble and accessible to plant roots, preventing deficiencies in actively growing tissues.
• Adjusting pH to neutral levels helps alleviate aluminum toxicity, allowing calcium to compete for soil binding sites.
• Balanced pH promotes optimal nutrient uptake, prevents calcium absorption from being hindered by other ions, and supports healthy plant growth.
• Water quality, influenced by factors such as bicarbonate levels and pH, directly affects the availability of critical nutrients like phosphorus, calcium, and micronutrients in crop fertigation, impacting overall crop health and productivity.

Regular soil and crop health monitoring and targeted fertilization practices are crucial in maintaining adequate calcium levels and sustaining profitable crop production. Our agronomists and team of product experts are here to help.