A man much wiser than me once said that the easiest way to change your soil is to move.
A man much wiser than me once said that the easiest way to change your soil is to move. Unfortunately, this is not always an option for most producers. Soils in southeast Kansas are classified, in general, to be heavy clay soils. On possible soil amendment that may help alleviate some of the issues caused by clay soils is gypsum (calcium sulfate dihydrate for the chemistry know-it-alls).
How does gypsum alter the soil? Potentially, it can improve soil aggregation. This simply means making larger particles of soil with better structure. Soils with better aggregation have improved water infiltration and a lower risk of runoff and erosion. Gypsum can also, potentially, lower aluminum toxicity in acidic soils and is a source of the essential plant nutrients calcium and sulfur.
DeAnn Presley, Kansas State University Soil Management Specialist conducted a study near Marion, Kansas. Across her study, five treatment levels were used. Before planting, 0, 0.5, 2.15, 4.30, and 8.60 tons per acre of mined gypsum were applied to the no-till grain sorghum field.
Prior to applying the amendment, soil samples were taken to get an accurate idea of how the added gypsum affected the field. Specifically, they wanted to know the level of cation (positively charged ions) concentrations. At harvest, grain yield, grain nitrogen and sulfur content were measured. After grain harvest, more soil samples were taken to measure stability. Also, they measured fertility components including pH, potassium, calcium, and sodium as well as the soil’s cation exchange capacity (a measure of how many cations a soil can hold).
As stated before, gypsum potentially can improve aggregation. Results from this study show that the highest level of gypsum (8.6 tons per acre) increased the number of large particles to a statistically significant amount higher than the other levels and reduced the amount of small particles to a statistically significant lower amount.
As expected, gypsum did not have any impact on the soil pH and increased the calcium concentration in the soil. However, there was no statistical difference in the grain levels of nitrogen or sulfur and, most importantly, no difference in yield.
It must be pointed out that these results came from a one year study. The potential benefits from applying gypsum may take more time to make the impact desired. For more information about gypsum, search for Gypsum as an Agricultural Amendment, by L. Chen and W.A. Dick of Ohio State University Extension.
If you are interested in participating in a gypsum research study on your farm please let me know. Additional research is being conducted and volunteers are needed. If you have questions or would like more information, please call me at the office (620) 724-8233, or e-mail me at firstname.lastname@example.org, or visit the Wildcat Extension District website at www.wildcatdistrict.ksu.edu.