How Manganese Affects Soil Health and Plant Growth

Manganese is a micronutrient that is essential for plant growth and development. It plays a key role in various physiological processes, such as photosynthesis, nitrogen metabolism, antioxidant synthesis, and defense against pathogens. Manganese also influences the availability and uptake of other nutrients, such as iron, zinc, copper, and calcium.

However, manganese availability in soils depends on several factors, such as soil pH, organic matter, moisture, temperature, and interactions with other elements. Manganese deficiency or toxicity occurs in some crops, but not all, and affects their yield and quality.

Soil Health and Manganese

Soil health is a complex concept that refers to the capacity of soil to sustain plant growth, maintain or enhance environmental quality, and support human health. Soil’s physical, chemical, and biological properties influence overall soil health. Farming management practices and environmental conditions also play key roles in the health of your farm. (1)

One of the chemical aspects of soil health is the availability of essential nutrients for plants, including manganese. Manganese in soils exists in different forms and oxidation states, but only the reduced form (Mn++) is readily absorbed by plants. The availability of Mn++ in the soil solution is affected by the following factors:

• Soil pH: Manganese solubility decreases as soil pH increases, due to the precipitation of manganese oxides and hydroxides, or the binding of manganese with organic matter. Therefore, manganese deficiency is more likely to occur in alkaline soils (pH > 7), especially in calcareous soils or over-limed soils. Manganese deficiency symptoms include young leaves’ interveinal chlorosis (yellowing between the veins), reduced growth, and lower yield.

• Organic matter: Organic matter can affect manganese availability in two ways. On one hand, organic matter can chelate manganese and make it more soluble and available for plants, especially in acidic soils. On the other hand, organic matter can also compete with plants for manganese uptake, or immobilize manganese by forming insoluble complexes, especially in alkaline soils. For example; muck soils are prone to have manganese deficiencies.

• Moisture and temperature: Moisture and temperature can influence manganese availability by affecting soil microbial activity, root growth, and plant metabolism. Under dry soil conditions, manganese availability is reduced, due to the decreased solubility and mobility of manganese in the soil. Under cold and wet conditions, manganese deficiency can occur, due to the reduced mineralization of organic matter, reduced root growth, and reduced metabolic activity in roots. On the other hand, when your soil is waterlogged, the availability of manganese increases. This can lead to manganese toxicity, which is characterized by dark brown spots or necrotic lesions on older leaves, stunted growth, and reduced yield. (2)

Manganese and Other Nutrients

Manganese interacts with other micro and macronutrients in plants, either synergistically or antagonistically. Some of the main interactions are:

• Iron: Manganese and iron have similar functions and uptake mechanisms in plants, and they can compete for the same transporters in roots. Therefore, high levels of manganese can inhibit iron uptake and induce iron deficiency, which is also manifested by interveinal chlorosis of young leaves. Conversely, high levels of iron can inhibit manganese uptake and induce manganese deficiency.

• Zinc: Manganese and zinc are both involved in enzyme activation and protein synthesis in plants, and they can enhance each other’s effects. However, excessive amounts of either nutrient can interfere with the other’s absorption and metabolism. For example, high levels of manganese can reduce zinc uptake and translocation, and vice versa.

• Copper: Manganese and copper are both involved in antioxidant defense and lignin biosynthesis in plants, and they can have positive or negative interactions depending on the crop and the environmental conditions. For example, in wheat, manganese can increase copper uptake and utilization, and improve resistance to fungal diseases. However, in barley, manganese can reduce copper uptake and induce copper deficiency, which can affect grain quality.

• Calcium: Manganese and calcium have opposite effects on cell wall structure and plant stability. Manganese promotes the synthesis of pectin, which is a component of the primary cell wall that provides flexibility and elasticity. Calcium cross-links pectin molecules and forms calcium pectate, which is a component of the middle lamella that provides rigidity and adhesion. Both nutrients are required for optimal cell wall function and integrity. However, high levels of either nutrient can impair the other’s role and affect cell wall properties. For example, high levels of manganese can reduce calcium uptake and deposition, and cause cell wall loosening and plasmolysis.

Balance Nutrients for Optimum Plant Growth

Manganese is a vital micronutrient for plant growth and development. But you can have too little or too much of a good thing. At ST Biologicals we recommend two different micronutrient products, depending on your farming practices and soil needs.

For our organic clients, we recommend Q-Bio?? Manganese 5.5 %. It is a polysaccharide complex that works with plants’ natural physiological processes to increase uptake and translocation of needed manganese. Sandy and alkaline soils are more apt to have manganese deficiencies and this product solves the problem.

For our traditional clients, we have partnered with Aqua-Yield? to offer their nanotechnology product, NanoPack?. It’s a balanced micronutrient soil amendment.

NanoPack delivers sulfur, copper, iron, manganese, and zinc through Aqua-Yield NLT-D technology. NanoPack brings critical micronutrients to plants when soil levels are low. When applied throughout the growing season, NanoPack helps prevent nutrient deficiencies that limit crop yield while boosting plant metabolism and overall health.

Nanotechnology is a cutting-edge technology that delivers nutrients or chemistry more efficiently into the plant through root or foliar uptake. It’s compatible with most liquid fertilizers and is easy to use.

Optimum crop yields and soil health are influenced by various factors, such as soil pH, organic matter, moisture, temperature, and interactions with other nutrients. It’s important to monitor manganese levels and apply appropriate fertilization practices to avoid manganese deficiency or toxicity, and to optimize soil health and plant productivity.

Whether you’re an organic or traditional farmer, the first step toward balanced soil nutrients and a profitable farm is a soil test.

When was the best time to have your soil tested? Last fall.

When is the second best time? Today.

At ST Biologicals, our certified crop consultants are committed to helping you succeed. Give us a call.

#nanopack?? #magnesium?? #nutrientbalance?? #soilhealth

References

1. Bacteria | Free Full-Text | Enhancing Manganese Availability for Plants through Microbial Potential: A Sustainable Approach for Improving Soil Health and Food Security (mdpi.com)
2. factsheet49.pdf (cornell.edu)