Plants need sulfur to thrive; unfortunately, it's often in short supply! Most of the soil-bound sulfurs are inaccessible to plants, so they rely on the anionic form found in water. Plants take up this sulfur using specialized transporters — but that’s not all! Sulfur also plays a crucial role as part of protein disulfide bonds & amino acids, plus acting as a mediator for stress management & normal metabolic processes. Although scarce compared with other nutrients, your veggie garden would be out of luck without sulfate!
When soil sulfur levels are low, plants rely on their symbiotic partners, bacteria and fungus, to help them acquire the element. Therefore, studying sulfur's role in plant metabolism from several angles is crucial for enhancing the health of plants and the animals and humans that rely on them.
Role of Sulfur in Plants
In plants, sulfur performs a wide range of important roles. Proteins, oils, and amino acids all rely on it. For example, it is a building block of two of the 21 amino acids that make up protein, is essential for creating chlorophyll, encourages nodulation in legumes, aids in the growth and activation of certain enzymes and vitamins, and is required for these processes.
Relation with Nitrogen
S is closely related to N in the crop's nutrient requirements. Both S and N are essential to protein and play a role in making chlorophyll. Thus, their closeness makes sense. S's participation in transforming nitrate into amino acids also connects these two processes. In general, plant species with a high need for nutrient N will also have substantial sulfur requirements.
Sulfur Deficiency
A lack of sulfur causes the whole plant to become a light yellow or green tint. The chlorosis causes the tips of the younger leaves to die off and become necrotic. Plants will not develop to their full potential without sufficient sulfur in the soil. Seedling mortality rates tend to spike immediately after transplantation. These symptoms match those of a nitrogen shortage. Nitrogen deficiency can cause red colouration in the veins of young leaves, but sulfur deficiency will not normally influence the vein patterns on leaves and is thus easier to miss.
It's common for soils to be sulfur deficient in wetter regions. Sulfur is a water-soluble element. Therefore, the soil loses its sulfur content when it rains heavily, and the plants suffer. In coastal places, sea spray may be a considerable supply of sulfur, yet even islands face sulfur deficits in their soil. In addition, areas with high amounts of phosphorus may remove sulfur from the earth, generating more significant levels of sulfur-deficient plants.
How to Deal with Sulfur Deficiency?
Increasing the amount of sulfur in your garden may be done in a few ways:
Adding mulch, manure, and organic matter may increase the quantities of micronutrients and macronutrients available to your plants if you feel that more than just sulfur may be deficient in your soil. In addition, rich mulch, manure, or other organic matter may increase most of the minerals.
When extreme measures are required, a fertilizer with sulfur powder may be the best alternative. Sulfur powder is targeted to the particular nutrient shortfall at issue rather than using a general approach to a specific problem.
Sources of Sulfur in Soil
Sulfur may be obtained from several different places in the ground. Most of the soil's sulfur is found in organic materials. If you break down any organic matter, some of the sulfur in that matter will be mineralized and made accessible to plants. Many of the soil's minerals, in addition to the organic matter, have their own unique sulfur compounds. Therefore, some of the sulfur in these minerals is converted to sulfate during the breakdown or weathering process.
The concentration of SO2 in the air is greater around major cities with large industrial zones. Sulfur may also be produced from the combustion of fuel. Sulfur dioxide, a gas, is produced (SO2). It is via the dissolution of this SO2 in precipitation that it ultimately reaches the ground. The quantity of sulfur added to the soil by pesticides is negligible. However, certain insecticides are made with sulfur, and their usage adds sulfur to the soil. In addition to nitrogen, potassium, and phosphorus, chemical fertilizers also include a significant quantity of sulfur.
How do Arbuscular Mycorrhiza Fungi (AMF) Contribute to Sulfur Production?
Soil-dwelling fungi called AMF are responsible for root colonization in plants. Vesicles, arbuscules, and hyphae are all structures produced by AMF in the root system, and the fungus also sends hyphae into the rhizosphere. As a bio-fertilizer, AMF boosts plant development by facilitating the absorption of water and mineral nutrients from the soil's rhizosphere. Multiple studies have shown the positive effects that AMF has on both crop yield and soil quality. As a result, some people think that AMF may stand in for traditional chemical fertilizers.
When Sulfur is lacking, fertilizers may be used as a supplement. Sulfur is essential for plant growth, but its availability to plants depends on factors such as the time and method of sulfur delivery.
Think Before You Make Sulfur Fertilization Decision
When deciding how much S to fertilize, it's important to weigh many things. Goals for crops and yields, plant and soil analyses, organic matter levels, soil texture, and inputs like irrigation water and manure are all factors to consider. Compared to grain crops, high-yielding forage crops like alfalfa and hybrid bermudagrass tend to be more sensitive since they remove more S.
Since sulfate is so mobile in the soil, it is crucial to collect soil samples from a greater depth than typical (0 to 2 feet) while conducting a soil test for sulfate (S). Deficiencies in S are most prevalent in soils with less than 2% organic matter, although they may also exist in soils with greater organic matter. Soils with a coarser texture are more likely to be deficient in S. However; deficiencies may also occur in soils with a finer texture. Knowing the sulfur content of irrigation water is important because, in certain circumstances, it might provide a lot of Sulfur.
Conclusion
Sulfur is essential for optimal crop growth, making it an increasingly important element in modern fertilization. Therefore, when considering how to support your crops' nutrition needs best, be sure to account for the crucial role of Sulfur!
