13 Key Nutrients for Plants – #9 Sulfur
Soil testing is an important activity for a successful garden. Soil stewardship is an ongoing process, where you test and amend, grow some stuff, then test, amend and grow some stuff….and so on. Focus on building soil tilth so it can really hold and make available to the plants all the important nutrients. You do this in part by adding compost, manure, rock dust, bone meal, kelp & fish emulsions. Read this article series to learn more about each of the 13 key nutrients for your garden.
Sulfur falls onto Ontario, Canada farms in the form of acid (sulfur dioxide) rain, depositing 8-13kg per hectare each year, so soil deficiency is not common here. Sulfur can be used as a soil amendment to correct high pH of above 7.0, and can help reduce higher levels of lime and sodium. Lime gets converted into gypsum which has the benefit of providing calcium. Sodium is freed so that leaching can remove it from the soil. Sulfur helps improve soil quality by building tilth, and also by reducing the tendency to crust by removing sodium. Sulfur also makes other nutrients like phosphorous more available.
Deficiencies in Sulfur will show as yellowing leaves, beginning with the younger leaves.
To correct a deficiency of Sulfur
- organic matter releases sulfur as it decomposes, and minerals in the soil can also slowly release it so add compost, worm casings and greensand and rock dust to prevent or treat a deficiency
- elemental Sulfur can be applied to provide a fast acting source
If too much sulfur is present it will negatively impact the plant’s ability to take in molybdenum. That can result in leaves that show curled mottled edges.
To offset excessive Sulfur
- Corn, alfalfa, wheat, legumes and oil seeds remove large amounts of sulfur.
- Add sand to the soil to increase leaching and help reduce accumulation of sulfur