Sulphur is an essential nutrient for proper plant growth and development. This macronutrient plays a critical role in various physiological functions and metabolic processes. In this blog post, we’ll discuss the functions of sulphur, how to recognize the symptoms of sulphur deficiency, the causes of this deficiency, and how to address it effectively.
Functions of Sulphur
Sulphur is integral to several vital processes in plants, and its demand in plants varies depending on the species and development stage, with higher amounts required during seed development and vegetative growth. Let’s see some of its main functions:
1. Protein Structure: It is a part of amino acids such as methionine and cysteine, as well as vitamins (biotin and thiamine), glutathione, chlorophyll, and coenzyme A.
2. Stress Management and Metabolic Processes: Sulphur and sulphur-containing compounds act as signalling molecules in stress management and normal metabolic functions. They help mediate complex signalling networks.
3. NPK Uptake: Sulphur supports and optimises the uptake and utilisation of the three primary macronutrients, nitrogen, phosphorus and potassium. Deficiencies of these three nutrients, and especially nitrogen, are also related to sulphur deficiency.
4. Secondary Metabolites: Sulphur is a component of several secondary metabolites necessary for the plant’s physiological functions, growth, and development. They also take part in crosstalk of complex signalling network as a mediator molecule.
5. Better production of oils and starch content in tubers. In relation to the above, it has been shown that if the plant has access to sufficient sulphur, the oil production of some fruits, cereals and seeds improves and the amount of starch in tubers increases.
How to Recognise the Symptoms of Sulphur Deficiency
Recognising sulphur deficiency in plants is crucial for timely intervention, especially in productive crops, as even a small deficiency will reduce crop quality. Here are the symptoms to look out for:
1. Pale Green to Yellow Leaves: Sulphur-deficient plants often display pale green to yellow leaves; the chlorosis starts in the younger leaves. This yellowing resembles nitrogen deficiency, but is usually more noticeable on younger leaves, which is the opposite of nitrogen deficiency.
2. Brown leaf tips: Following discolouration and yellowing, brown spots appear on the edges and tips of the leaves, spreading inwards and throughout the leaf, which eventually dies.
3. Stunted Growth: Deficient plants are typically smaller with narrow, often yellowish leaves. The stems are thin, and longitudinal growth is inhibited.
4. Quality and Yield: A mild sulphur deficiency can have a small effect on the yield, but it will have a significant effect on the quality of it.
Causes of Sulphur Deficiency
Most of the sulphur in soil is present in organic matter and hence not accessible to the plants. Anionic form of sulphur (SO42-) is the primary source of sulphur for plants that are generally present in minimal amounts in the soil, and it is water-soluble, so readily leaches out of the soil. Here we recap several factors that contribute to sulphur deficiency in plants:
1. Low organic matter content: The organic matter content of the soil is crucial, and if it is low, plants are likely to be deficient in sulphur. The anionic form of sulphur (SO42-) is the primary source for plants but is often found in trace amounts in the soil. The organic sulphur contained in organic matter must undergo a process of mineralisation by micro-organisms to make it available.
2. Leaching: Sulphate is water-soluble and can easily leach out of the soil, especially in sandy soils or areas with high rainfall.
3. Soil Moisture and Temperature: The availability of sulphur from organic matter depends on microbial activity, which is influenced by soil temperature and moisture content. Cold, excessively wet, or dry conditions can reduce microbial activity and sulphur availability.
4. Soil pH: Sulphur availability is optimal at a pH of around 6.0. Variations in soil pH can affect sulphur uptake.
When gardening outdoors, you need to consider that the availability of sulphur in the soil can vary greatly across different areas of your garden due to differences in soil organic matter and texture. Sulphur deficiency is often found in sandy soils, which tend to have lower organic matter and are more prone to nutrient leaching. This is also common in higher elevation areas of a field where organic matter is naturally lower. In contrast, areas with high organic matter, such as lower-lying parts of a field, and soils with heavier and rich textures, usually have adequate sulphur levels. These soils can retain nutrients more effectively, making sulphur more accessible to plants. Therefore, understanding the specific characteristics of your garden soil is essential for managing sulphur levels and preventing deficiencies.
How to Address Sulphur Deficiency
By understanding the causes, we can tackle sulphur deficiency. But how? Let’s look at several strategies:
1. Increase soil organic matter: Increase the organic content of the soil by adding compost or organic fertiliser. This will increase the microbial activity necessary for sulphur mineralisation.
2. Sulphur fertilisers: Apply sulphur-containing fertilisers to replenish sulphur levels in the soil. If you cannot rely on organic matter and want to provide the plant with a more stable, direct and quickly accessible source of nutrients, using balanced fertilisers with sulphur on their formulas is the solution. Atami’s base fertilisers provide all the essential nutrients for your plants. And with our additives, you can customise and optimise the nutrition according to your specific needs. If you’re interested, take a look at our base fertilisers and, for additional sulphur, consider our Flavor additive, which not only provides sulphur, but also enhances the natural flavours and aromas of your crop.
3. Soil testing and pH management: Regular soil testing can help monitor sulphur levels and soil pH. Adjusting the pH to around 6.0 can improve sulphur availability.
4. Water management: Proper irrigation practices can help control sulphur leaching, especially on sandy soils. Avoid over-watering and ensure good drainage, but keep the soil moist, so microorganisms can stay active and transform organic sulphur.
Conclusion
Sulphur is a critical nutrient for plant health, influencing everything from growth to stress management. Recognizing and addressing sulphur deficiency promptly can prevent significant yield and quality losses. By understanding the functions of sulphur, identifying deficiency symptoms, and implementing effective solutions, you can ensure your plants thrive.
For reliable and effective solutions to sulphur deficiency and other plant nutrition needs, consider using Atami products. Visit our website to explore our range of high-quality plant care solutions, learn about other plant deficiencies and keep your garden flourishing. Happy gardening!
