Clark County Extension Service | 1400 Fortune Drive | Winchester, KY 40391 | 859-744-4682 | http://clark.ca.uky.edu/

Spring Soil Sampling Season

Don’t get behind on production this spring waiting on soil sample results, get your samples into the Extension Office early, so we can get your sample results back to you in a timely manner! As the spring planting season ramps up, the UK soil lab is bombarded with samples to calculate. Getting your soil samples turned in as soon as possible greatly reduces the possibility of waiting on samples and holding up your spring planting decisions. As always, soil sampling is a free service we offer our clientele here at the Clark County Extension Office. Bring your spring soil samples by so we can work up results for you and aid in your cropping decisions. Current wait time on sample results is approximately two weeks.

February was one for the books! We have endured the worst stretch of winter weather that we have seen in the last several years, and I think everyone is looking ahead toward spring! At this point hay supplies seem to be adequate to get us to spring green up, hopefully we will not have any more traumatic weather events that could change that. In this

newsletter you will find a few more timely meetings that are coming up including restricted use pesticide certification. If you have young folks at home, you might also want to check out information about the Youth CAIP program. As always, if you have any questions or concerns about anything in this newsletter feel free to reach out to us at the Clark County Extension Office!

Clay Stamm

Clark County Extension Agent for Agriculture & Natural Resources clay.stamm@uky.edu

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When your only tool is a hammer, everything looks like a nail. So goes an old joke about someone who

seems to be fixed on one issue or action. Applying enough fertilizer potassium (K) to forage crops seems to

be my recent hammer. Truly it is too simplistic to think potassium application fixes every problem, but an

increasing number of my farm forage inquiries end up involving a lot of discussion about potassium. What I

hope to do with this article is to help you better understand potassium and its importance in forage production.

First potassium is an essential nutrient for plant production. It is involved in plant water relations - opening

and closing of the leaf pores that regulate water flow through the plant. Potassium is also needed for plants to

fully express their disease resistance. And potassium is well known for its role in the expression of winter-

hardiness in perennial forage crops.

Potassium is removed in large quantities by forage crops, especially hay crops. Each ton of forage will

remove as much as 50 or 60 lb of K2O per acre, which is about three to four times the removal rate of

phosphorous (as P2O5). Using only nitrogen fertilizer or triple-19 (19-19-19) over a long period of time winds

up with sky high P numbers and K values in the basement.

Soils differ in their ability to supply potassium to plants. For example, the Eden soils of Northern Kentucky

typically have high levels of K and readily release it to crops. On the other hand, the Tilsit sandstone soils

around Princeton are low in K and do not release it very readily. Frankly the reasons behind the K-supplying

ability of soils is beyond my capability to explain and the space available in this column. The best way to

determine K status of soils is through a soil test.

Plants differ in their need for potassium. A low K test may call for 180 lb/A of K2O for grass hay but double

that for alfalfa.

Timing matters. When K is applied to forages in the early spring, plants take up more potassium needed, a

process called luxury consumption. Fall is the preferred time to apply potassium to avoid luxury consumption.

When large amounts of K2O are needed, a split application may be needed, such as after the first cutting and

in the early fall. With potassium and perennial forage crops, you are playing the long game for future returns.

Spring-applied potassium on grass pasture fields causes double trouble with grass tetany or

hypomagnesemia. High soil K inhibits the uptake of magnesium by forage crops, and the resulting high K

forage inhibit the uptake of Mg in the rumen. Grass tetany is most frequently seen in mature cows in early

lactation. These cows cannot mobilize Mg from their bones fast enough to replenish that lost in milk, leading

to tetany.

So how do you develop a potassium plan for forage crops? Here are the key takeaways:

By Dr. Jimmy Henning, First published in The Farmer’s Pride

√ Soil test and soil test often. Take the soil sample well after the last application of K as possible, such as each year after the last cutting right before applying fertilizer.

√ Make sure your pH is in the right range. Do not add lime when your pH is too high. If your soil pH is ow, apply lime according to UK guidelines. This will maximize the effectiveness of the K you add. If your pH is low and you lime appropriately you might see your STK jump up n response without adding any K.

√ Get your fertilizer custom blended to match soil test results. In fields with historic application of Triple 19 we see soil test P go through the roof and soil test K down in the basement. This is costly and impacts the environment. Stop adding P if you're over the optimum range.

√ Add K according to the soil test recommendations and if you're up near the top of K recommendations you'll want to split that application.

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Limited seating will be available, advanced registration is required. Masks and social distancing will be enforced.

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Youth Agricultural Incentives Program (YAIP) is a cost share program designed

for applicants that are enrolled in elementary, middle, high school or home

school, that are at least 9 years of age by January 1, 2021, and are actively

engaged in agriculture. Applications will be available at the Clark County

Conservation District Office at 667 Tech Drive starting Monday, March 1, until

Friday, March 19, 2021 during the hours of 8:30 am to 4:00 pm, Monday

• Agricultural Diversification •

• Supervised Agriculture Experience •

• Forage & Grain Improvement •

• Animal Production •

• Country Ham Projects •

• Showmanship •

Maximum local cost share is $1,500.00 on a 50/50 matching basis upon the

investment area completion. Submit education certification form, project

Invoices & proof of payment for cost share reimbursement. (No cash receipts)

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We have scheduled a Restricted Use Pesticide Certification Training via Zoom on Thursday, March 11. The certification is good for three years. Please check your card to see if it has expired. If it has expired or you have never been certified, please choose one of the times listed above.

The link for the Zoom meeting for each time slot is listed below. You will need to call the Extension Office at (859) 744-4682 to reserve a spot and to get the code for the meeting.

Thursday, March 11 12:00 noon OR 6:00 p.m.

Zoom Link for 12:00 noon meeting:

https://uky.zoom.us/j/88390281752?pwd=Y1hXVVRLUjRVSzM3S0FQaWh4SFdaUT09

Zoom Link for 6:00 pm meeting:

https://uky.zoom.us/j/84760438867?pwd=OE1NYyt0S2EzczJGdjh5cGh6dUNhZz09