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.ÌýModerate drought is expanding in the central part of the state.ÌýThe 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.ÌýThe 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.Ìý
Last week’s column discussed the possible negative effects of soil pH with low (acid) and high (alkaline) pH for our common crops.ÌýOur crops, and beneficial soil organisms prefer a soil pH of approximately 6.2 to 7.2, slight acid to very slightly alkaline.ÌýToday, what can be done to cope with soil pH when it’s out of that range.
Let’s deal with high pH, alkaline soils first.ÌýTypically, as long as the soil doesn’t have a high salt content and it’s under 8.5, we typically don’t worry much.ÌýOccasionally 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.ÌýYou can try to apply iron as a foliar spray but it can potentially damage the crop, isn’t cheap, and may or may not work.ÌýThe better suggestion is to plant more tolerant crops.ÌýAt high pH, there are applications to lower pH such as elemental sulfur or even sulfuric acid.ÌýHowever, these are extremely expensive and impractical on a crop field basis.ÌýIt may be practical for a small area such as a flower bed for acid loving flowering plants or even with certain crops like blueberries.ÌýA problem you should correct is a combination of high soil pH with high salt content.ÌýHere the most practical option is calcium sulfate, gypsum.ÌýThe calcium can displace the sodium and allow it leach with rainfall or irrigation below the root zone.
Acid soils are more practical to correct.ÌýAcid soils in our area are more likely found on the sandy soils of our region, in South Central Kansas, and especially Southeast Kansas.ÌýYou may find acid soils in North Central and Northeast Kansas but typically not to as great an extent.Ìý
There are several products to raise soil pH but the most common and practical is calcitic limestone, Ag Lime.ÌýDolomitic lime, which contains both calcium and magnesium carbonate is also an option.ÌýThe amount you will need is a function of soil type, organic matter content, and the actual pH.ÌýIf a soil test indicates acid soil conditions, a Lime Test Index, will tell you how much you need.ÌýHeavier, higher clay content soils, require more than lighter sandier soils but require liming less often.ÌýHigher organic matter content also increases the amount of lime needed.ÌýThere are other factors such as the purity and fineness of the material that matter.ÌýThe key is Ag lime is crushed rock and take time to work.ÌýIt needs incorporation and moisture to raise soil pH.
Finally, if you can’t lime for whatever reason, there are some cheats.ÌýFor wheat farmers, you can select an acid tolerant variety.ÌýAnd adding phosphorus in the row at planting can help.