The drought monitor report as of Tuesday, September 15, indicates continued dry conditions. Almost all of Barton County and much of the surrounding area in moderate/severe drought with more and most of Stafford and Rice Counties in severe drought. The northeastern third of the state is now in abnormally dry conditions. Only 9% of the state is out of dry conditions. The six to ten-day forecast (September 22 to 26) indicates a 30 to 50% chance of leaning above normal for temperatures and 33 to 0% of leaning above normal for precipitation. The eight to fourteen-day forecast indicates (September 24 to 30) indicates a 40 to 50% chance of leaning above normal for temperatures and a 33 to 40% chance of leaning above normal for precipitation.
Today’s topic may seem a bit different but as wheat planting nears, hopefully, it pays to discuss sulfur, it’s importance in crop production, and the latest price challenge for producers. Producers are already dealing with historically high fuel and nitrogen prices and now they can add sulfur fertilizer to the list.
When people think about fertilizing plants, from crop fields to backyard gardens and lawns, nitrogen, phosphorous, and perhaps potassium come to mind. Even though it’s a macronutrient, sulfur (S) is often neglected. Sulfur is found in certain amino acids like methionine and cystine. These amino acids are necessary as part of plant proteins. S is necessary to reduce nitrate nitrogen to a form for plants to make amino acids. It’s needed in the formation of chlorophyll. Sulfur deficiencies result in lower protein levels in wheat; inhibit seed formation; lower protein levels in alfalfa; and lower protein levels and yield in soybeans. Lack of sulfur intake can result in malnutrition in humans and animals. Biotin and thiamine are vitamins containing sulfur.
S deficiencies appear in younger plant tissue as it’s immobile in plants. Sulfur in the soil is primarily found as the sulfate anion (it carries a negative charge) in the soil. Typically, 95% of soil sulfur is tied up in organic matter and released in the available inorganic form through bacterial mineralization. Irrigators often have S in the water they apply. Deficiencies are becoming more common for a variety of reasons and are especially common on the sandy, low organic matter soils south of the Arkansas River. On these soils many producers apply sulfur for their wheat and alfalfa crops without even soil testing as they need it. S deficiency are becoming more common on our heavier soils as organic matter levels have decreased and after over a century of production agriculture. Plants don’t need as much S as nitrogen and typically about as much as phosphorous. So not a huge amount but vital for adequate seed production and protein levels along with adequate protein in alfalfa.