Great Bend Tribune
Published April 13, 2024
The drought monitor report as of April 9 is showing conditions moving from no dryness to abnormally dry for much of Southwest Kansas and we are still mostly abnormally dry.听Moderate drought is expanding in the central part of the state.听The six to ten-day outlook (April 17 to 21) indicates leaning to slightly below normal temperatures and a 33 to 40% chance of leaning to above normal precipitation.听The eight to fourteen-day outlook (April 19 to 25) indicates near normal for temperatures and a continued 33 to 40% leaning above normal for precipitation.听
Last week鈥檚 column discussed the possible negative effects of soil pH with low (acid) and high (alkaline) pH for our common crops.听Our crops, and beneficial soil organisms prefer a soil pH of approximately 6.2 to 7.2, slight acid to very slightly alkaline.听Today, what can be done to cope with soil pH when it鈥檚 out of that range.
Let鈥檚 deal with high pH, alkaline soils first.听Typically, as long as the soil doesn鈥檛 have a high salt content and it鈥檚 under 8.5, we typically don鈥檛 worry much.听Occasionally at a pH of 8, but typically higher, we may see crops such as soybeans exhibit an iron deficiency, especially is parts of Southwest Kansas.听You can try to apply iron as a foliar spray but it can potentially damage the crop, isn鈥檛 cheap, and may or may not work.听The better suggestion is to plant more tolerant crops.听At high pH, there are applications to lower pH such as elemental sulfur or even sulfuric acid.听However, these are extremely expensive and impractical on a crop field basis.听It may be practical for a small area such as a flower bed for acid loving flowering plants or even with certain crops like blueberries.听A problem you should correct is a combination of high soil pH with high salt content.听Here the most practical option is calcium sulfate, gypsum.听The calcium can displace the sodium and allow it leach with rainfall or irrigation below the root zone.
Acid soils are more practical to correct.听Acid soils in our area are more likely found on the sandy soils of our region, in South Central Kansas, and especially Southeast Kansas.听You may find acid soils in North Central and Northeast Kansas but typically not to as great an extent.听
There are several products to raise soil pH but the most common and practical is calcitic limestone, Ag Lime.听Dolomitic lime, which contains both calcium and magnesium carbonate is also an option.听The amount you will need is a function of soil type, organic matter content, and the actual pH.听If a soil test indicates acid soil conditions, a Lime Test Index, will tell you how much you need.听Heavier, higher clay content soils, require more than lighter sandier soils but require liming less often.听Higher organic matter content also increases the amount of lime needed.听There are other factors such as the purity and fineness of the material that matter.听The key is Ag lime is crushed rock and take time to work.听It needs incorporation and moisture to raise soil pH.
Finally, if you can鈥檛 lime for whatever reason, there are some cheats.听For wheat farmers, you can select an acid tolerant variety.听And adding phosphorus in the row at planting can help.