# Bermuda Fertility



## terraceridge (Jul 21, 2011)

I bale about 15 acres of coastal bermuda for the horse market in NC. My yields have been getting steadily worse over the past few years. I am now down to about 2000-2400 square bales (about 3-4 tons per acre) off of all my land. I would like to get 3000-3500 bales (about 5-6 tons per acre). I have also been experiencing increased weed pressure recently. My soil tests show 141-262 units phosphorous, 22-34 units potassium, and a pH of 5.9-6.5 (by the way, what units are the potassium and phosphorous measured in? Are they parts per million?). My hay analysis shows 1.25% potassium and .24% phosphorous on a dry matter basis. My fertilizer regimen in the past has been 200 lbs 34-0-0 at green up and 200 lbs after every cutting except the last. Do you all think I would benefit from adding potash? If so, how much? Are there any other recommendations? Thanks!


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## dubltrubl (Jul 19, 2010)

To me, it looks like your a bit low on potash. Keep in mind bermuda will remove almost as much potash as nitrogen for a ton of hay. I firmly believe it helped us last year having a lot of potash applied prior to a drought. Wasn't my intention though. What the plan originally was, was to get the potassium percentage up since we were a bit behind, then a drought hit. Turns out, we made a lot of very good hay even during dry times and the analysis didn't change much even after applying more potash than was recommended. That really opened my eyes as to what bermuda really will use in the form of potash. In the future, I'll never skimp on potash again. It's gonna get all it wants, and then some. Just my $.02. Best of luck!
Steve


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## Canderson012 (Jan 17, 2012)

From what the guys at the fertilizer store tell me, pot ash is key in making hay. When you cut you take all the grass clippings with you so over a year or so of hay baling there are no natural fertilizers going back into the ground.


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## darwood (Jun 7, 2010)

Bermuda needs to run at the 300 lbs per acre of soil test K to remain healthy and in high production. After every cutting, besides the N you need to be adding at least 50 to 60 lbs of K back to the soil. Over time K levels can fall off quickly if the K is not added back. There is a ton of data on this out there for you to examine.


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## vhaby (Dec 30, 2009)

There appears to be a bit of confusion in these posts. Soil test results normally are reported in parts per million (ppm) or pounds per acre depending on the whims of the testing lab. The term "unit" is a misrepresentation of soil test results. Unit is an old term used to indicate an amount of fertilizer such as 20 lbs and this term is no longer used in that regard.

Soil test results for potassium are reported as K. Fertilizer K is applied as potash which is referred to as K2O, but actually is potassium chloride (KCl). Yes there is a lot of data available that shows the response of hybrid bermudagrasses to potassium, but most of that data overlooked the effect of chloride on yield of bermudagrass. Recent data has verified that, in addition to bermudagrass responding to potassium, Tifton 85 bermudagrass also responded with increasing yield to the chloride applied as potash. Yield response to potassium sulfate was lower than response to potassium chloride when equal rates of potassium were applied from either source.

Also, older data that showed the need to fertilize bermudagrass with a 3 to 2 ratio of nitrogen to potassium are outdated. The most recent data indicate the need to apply equal amounts of nitrogen and potash (K2O) for bermudagrass production. This is kind of hard to do with current prices for both fertilizer materials, but especially for potash.

Soil test K levels vary by soil type. Most clay soils will test higher in K than will sandy loam soils. Sandy loam soils can produce excellent yields of bermudagrass hay when the soil test indicates only about 40 or so ppm K as long as equal amounts of nitrogen and potash are applied, in the range of 300 lb or more of each/acre. When potash is omitted, bermudagrass stand density rapidly declines and yield suffers as a consequence. Not only does yield of surface vegetation decline, the production of rhizomes also declines. Increasing the soil test level of K from the level indicated in the original post on this thread to 150 ppm or 300 lb/acre will take years of applying high rates of potash and at current prices of potash, will be uneconomical. Maintaining the current soil test level of K by applying the amount of K removed in hay will work to sustain stand density and yield of bermudagrass. Application of 45 to 50 lb of K2O per ton of bermudagrass hay removed should be about right.


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## terraceridge (Jul 21, 2011)

When you say 300 lbs of potash and nitrogen, do you mean actual nutrients or total applied fertilizer? In other words, should I put out 300 lbs of 0-0-60 or 500 lbs of 0-0-60 (500x.6=300)? And how about nitrogen? Should I put out 300 lbs of 34-0-0 or 900 lbs of 34-0-0 (900x.34=306)?


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## darwood (Jun 7, 2010)

When I said 300 lbs of K / acre, I was refering to the amount of K presently in the soil profile, and yes this takes years to accumulate through commercial fertilizer sources, or if you have access to poultry or some other manure source it can be done, but as previously mentioned it is exspensive. When cutting bermuda for hay prior to the first cut and prior to subsequent cuttings one needs to add the N and K in the area of 50 to 60 actual lbs of each per acre. I usually reccommend 150 lbs amonium nitrate or 100 lbs urea along with 100 lbs of K20 per cutting. by doing this you are at least replacing what you are taking from the soil per cutting.


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## terraceridge (Jul 21, 2011)

Vhaby said that bermuda removes 45-50 lbs of potash per ton and I read somewhere else that it also takes 50-60 lbs of nitrogen. Doesn't that mean that 150 lbs of ammonium nitrate and 100 lbs of potash will only support 1-1.5 tons per acre per cutting?


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## hay wilson in TX (Jan 28, 2009)

You can do the math. 
In round numbers 12% CP is 2% nitrogen, & a reasonable potassium level is in the 2% K range.

Two percent of 2,000 lbs is 40 pounds. 
For 10% CP there is 32 lbs/T of hay, yet the general rule of thumb is 50 lbs/A N for a ton of hay.

Application of 45 to 50 lb of K2O per ton of bermudagrass hay removed should be about right. vhaby

That is a true statement if there ever was one. 
Personnel experience is I get a better response to 500 lbs/ A 0-0-60 ( 300 lbs K20) if I also add 100 lbs of K-Mag. for the sulfur. I suspect ammonium sulfate would do just as well as the K-Mag.


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## HWooldridge (Oct 13, 2010)

I square bale 12 acres of coastal for the horse trade in Central Texas. This comes off heavy clay soil and the biggest single yield improvement I've made aside from weed control is to aerate every two years. I built my own shop made version of a Hay King Pasture Renovator and it cuts a nice groove about 5-6" deep. I cross hatch the field after spring rains and the coastal comes up gangbusters when the weather warms up. If I keep the broadleaf and johnson grass down, I'll get 4 tons of hay per acre. The biggest problem we have is inconsistent rain - I'd get 5-6 tons if I could irrigate.


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## vhaby (Dec 30, 2009)

terraceridge said:


> When you say 300 lbs of potash and nitrogen, do you mean actual nutrients or total applied fertilizer? In other words, should I put out 300 lbs of 0-0-60 or 500 lbs of 0-0-60 (500x.6=300)? And how about nitrogen? Should I put out 300 lbs of 34-0-0 or 900 lbs of 34-0-0 (900x.34=306)?


I'm sorry my comments were not clear. The biological response of hybrid bermudagrass usually peaks somewhere in the range of 90 to 100 lb of nitrogen per acre per cutting. So, if you need the hay, or sell hay and expect three or more cuttings, you would want to consider application of 100 lb of actual nitrogen and the same amount of actual potash for each cutting on relatively sandy soils such as sandy loam. If haying on a clay soil, you might consider the method suggested by Hay Wilson, if you can afford that much K2O at one time, and then pray for rain. Also, don't forget about phosphorus, sulfur, etc. if the soil test for these plant nutrients is in the low and medium range. Even if these plant nutrients are in the low end of the high range, a small amount of these nutrients will help maintain that level in the soil.


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## vhaby (Dec 30, 2009)

hay wilson in TX said:


> You can do the math.
> In round numbers 12% CP is 2% nitrogen, & a reasonable potassium level is in the 2% K range.
> 
> Two percent of 2,000 lbs is 40 pounds. For 10% CP there is 32 lbs/T of hay, yet the general rule of thumb is 50 lbs/A N for a ton of hay.
> ...


The reason that I say apply 45 to 50 lb of K2O per ton goes like this. There are two potassium molecules and one oxygen molecule in K2O. Based on formula weight (a chemistry term), there is 83% potassium in K2O, or 0.83 of the total weight of K2O is potassium. Plants take up potassium as K, not as K2O shown on the fertilizer bag or blend sheet. So, if bermudagrass takes up 40 lb of K per ton of dry matter produced, then application of 50 lb of K2O for each ton of expected yield gives 50 x 0.83 = 41.5 lb of K applied, and we are assuming that all of the applied K is taken up by the plant. This may be closer to true in a sandy loam soil than in a clay soil where some of the applied K is fixed in the clay mineral of adsorbed onto, and tightly held by the clay..


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## charlesmontgomery (Jun 4, 2011)

HWooldridge said:


> I square bale 12 acres of coastal for the horse trade in Central Texas. This comes off heavy clay soil and the biggest single yield improvement I've made aside from weed control is to aerate every two years. I built my own shop made version of a Hay King Pasture Renovator and it cuts a nice groove about 5-6" deep. I cross hatch the field after spring rains and the coastal comes up gangbusters when the weather warms up. If I keep the broadleaf and johnson grass down, I'll get 4 tons of hay per acre. The biggest problem we have is inconsistent rain - I'd get 5-6 tons if I could irrigate.


Tests have shown that aeration has no or very little benefits. If you have clay soils they crack ever year as it gets dry. Didn't yours get cracks as big as Texas during the drought last year. ever tried sticking a stick down one? they go on forever. Aeration is a waste of diesel.


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## HWooldridge (Oct 13, 2010)

charlesmontgomery said:


> Tests have shown that aeration has no or very little benefits. If you have clay soils they crack ever year as it gets dry. Didn't yours get cracks as big as Texas during the drought last year. ever tried sticking a stick down one? they go on forever. Aeration is a waste of diesel.


You may be right over the long haul but the grass always gets started growing earlier in those years when we renovate. I can say that with certainty because I take care of another 6 acres for a next door neighbor and his field is slower than mine to green up - but only when I run the chisel. I've thought it might be because the ground gets warmer quicker when there is more bare dirt showing instead of mulch left over from the previous year's cut.


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## hay wilson in TX (Jan 28, 2009)

charlesmontgomery said:


> Tests have shown that aeration has no or very little benefits. If you have clay soils they crack ever year as it gets dry. Didn't yours get cracks as big as Texas during the drought last year. ever tried sticking a stick down one? they go on forever. Aeration is a waste of diesel.


This is an interesting Paradox a truly interesting Paradox.

All most universally our University trials say aeration is a waste of time and effort.

A number of hay and pasture forage growers find aeration to improve water infiltration. Aeration is also a favorite with the Golf Course Keepers.

Fellow in Idaho who manages 5,000 acres of irrigated alfalfa and he recommends aeration.

A Bermudagrass grower near Bandera, TX also swears by aeration.

Yes our clay soils crack wide and deep, and in theory this aerates these soils. Unless of course the early rains are slow and gentle so the cracks close before the rain water has an opportunity to get deep.

Water that floods over the ground will pack the ground. Ask me how I know!

With all that there is not an aerator on the place. Some times I could use one, but other times I would not get around to using it.

The Long and the Short of it is, Sometimes on some soils aeration is useful, and possibly necessary. On one ranch I saw where they used a bulldozer with a single shank subsoiler to renovate their range land. That one was thought up, laid out, and monitored by NRCS. Worked like a champ.

If aeration works for you, feel blessed, or cursed as the case may be.


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## hay wilson in TX (Jan 28, 2009)

The Ranch bulldozer chisel plow was on the conture and with 50 or so feet between chisel tracks.


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## Thad (Nov 29, 2011)

I think that aeration works just look at the grass growing in a fire ant mound. I hate thim SOB'es but if we could find a way to aerate the way that they do we could all grow more hay.


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## terraceridge (Jul 21, 2011)

Thad said:


> I think that aeration works just look at the grass growing in a fire ant mound. I hate thim SOB'es but if we could find a way to aerate the way that they do we could all grow more hay.


Good point. I have always wondered why hay grows so much taller and darker green in a fire ant mound and the best thing I can figure is, like you, that they aerate the soil. I guess they loosen the ground from underneath without disturbing the growing plant. I have also wondered if they add some nutrient to the soil through their daily processes.


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## jdhayboy (Aug 20, 2010)

Thad, funny u say that i have seen that and taken notice. Aeration is just so hard for me to judge if its beneficial or not. One year I've thought 'it helped me absorb moisture' another year 'I'm cussing it saying dried out my soil.' I honestly cant say its good or bad. To me, its hard to see results. Mostly its opinions of people saying they believed it helped their soil.
By the way, I am going to use it on some old rice ground we have planted in coastal. Rice ground has a very bad hard pan. This ground does not crack like clay, it is like concrete. Even though i am not expecting to see results I cannot help but feel that will help in this situation.
One thing about farmer that i like is trying new things and gathering my own results. I can tell you in my little community where I live not everybody has the same ideas about the techniques we all use. And I honestly cant couldn't tell you which one is right or wrong. Farming is dang near all a gamble anyway. If you like it, go for it.


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