Why fertilize with sulfur?

In the past, a large part of the sulfur requirement of plants was obtained by sulfur deposition from the air. Due to desulfurization of flue gases from industry, sulfur deposition has become increasingly smaller. Nowadays there are risks of sulfur deficiencies in crops. Sulfur fertilization is necessary to prevent these deficiencies. 

Crops do not all have the same sulfur requirements. Cruciferous plants, such as cabbage and rapeseed, have a high sulfur requirement. Grassland also needs a lot of sulfur (S). For the crops mentioned, there is often a need early in the year and/or in a short period when the sulfur requirement of the crop is high.

The sulfur requirement of arable and vegetable crops is divided into four categories:

• Very high requirement: 50-60 kg S for Brussels sprouts and head cabbage
• High requirement: 40-50 kg S for cauliflower, Chinese cabbage, celeriac and rapeseed
• Moderate requirement: 20-30 kg S for consumption and starch potatoes, kale, broccoli, grains, grass seed, carrots, peas, green beans, leek, silage maize and onions
• Low requirement: 15-20 kg S for seed potatoes, lettuce, sugar beet and flax

Sulfur sources for the plant
Sulfur sources for the plant are diverse, including S-min (soil supply of mineral sulphur), deposition (sulfur from precipitation), capillary rise (sulphate from groundwater), irrigation (irrigation water may contain sulphate) and the sulfur supply capacity of the soil (SLV). , where sulfur is released from the decomposition of organic matter.

Sulfur in the soil
The sulphur-producing capacity of the soil (SLV) needs some additional explanation. Sulfur is released by mineralization of organic matter in the soil, which requires soil temperature and moisture. Most mineralization takes place in the second half of the year when the soil has sufficient temperature and soil life is active. Plants that need a lot of sulfur early in the spring, such as grains and grasses, do not receive enough sulfur from mineralization in the spring and benefit from sulfur fertilization.

Sulfur fertilization
Not every sulfur compound can be absorbed by the plant; the plant absorbs sulfur (S) in the form of sulphate (SO42-). It is important to take this into account when interpreting sulfur advisories, which are often stated in kilograms of sulfur (S) and not sulphate. Sulfur can be applied with fertilizer or organic fertilizer. Artificial fertilizer is often readily available, while organic fertilizer is dependent on mineralization.

Synergy between sulfur and nitrogen
The latest addition to the field of nitrogen-sulfur fertilizer is Dynamon from OCI. This fertilizer has an ideal N/S ratio of 24% N and 7% S. The synergy between nitrogen and sulfur is unique. If both elements are available in sufficient quantities, a plant can absorb and utilize N and S effectively and easily. Even more important: to make proteins, the plant needs nitrogen and sulfur. If any of the elements are missing, synthesis is affected, affecting yield and quality. Dynamon is applicable and effective in all arable crops.

Want to know more about OCI Dynamon? Read the information www.oci-dynamon.nl.