Watch: Why Are Sandy Soils Prone to Sulfur Deficiency?
What causes sulfur deficiency in sandy soils?
Sulfur deficiency is a common problem in sandy (or course-textured) soil due to its low organic matter. This is because approximately 95% of sulfur found in soil is contained in organic matter.
In the United States, sandy soils are found across a 12-State region that includes Nebraska, South Dakota, Wyoming, Texas, and New Mexico. While in Canada, sandy soils can be found nearly everywhere crops are grown.
How can farmers prevent sulfur deficiency
The other challenge is that sandy soil is loosely structured, making it prone to leaching.
For this reason, sulfate-based fertilizers (including ammonium sulfate) may not be ideal beyond providing immediate sulfur at the start of the growing season. There is an increased risk of the sulfate leaching into the soil – beyond the reach of the plants. From an economic standpoint, if a fertilizer is leaching, it is not money well spent. Leaching can also pose environmental concerns in areas near sensitive water bodies.
Degradable elemental sulfur fertilizers are particularly well suited to meeting the need for a season-long sulfur source in sandy soils. Not only do they provide a high sulfur analysis at an economical cost, but sulfur also will not leach in its elemental state. Bentonite sulfur pastilles slowly convert from elemental sulfur to sulfate sulfur over the growing season – at a conversion rate of 30% to 40% per year.
Initially, the degradable elemental sulfur will need to be supplemented by a small amount of ammonium sulfate to meet initial sulfur demand in the early crop stages. This requirement can be reduced if elemental sulfur is applied as an annual fertility strategy.
H2: The good news?
“Some of North America’s best crops are grown in sandy soils. With the right management strategies, it can be amazingly productive,” explains Ray Dowbenko, an independent agronomist.
Dowbenko suggests that those growing in sandy soils consult with a locally based agronomist to determine the most agronomically and economically sound fertility strategy.