Pro-Line

I am attempting to get my soil ready for a fall planting. I've done the soil tests, and I needed to lime (done) and add potassium. I am going to spread the proper amounts (250lbs/acre) of potash to correct the pH.

Question...should I thow on some 12-12-12 also? It was reccommended to me by a fellow I work with that cuts 100+ acres of alfalfa each year. He said when he plants alfalfa or clover, he limes and spreads 12-12-12 to get it to green up and make it stronger.

Is there any scientific backing to his logic? Will spreading the 12-12-12 hurt?

Thanks.

doughboysigep

consult with a local agronomist (extension agent, university, or the fertlizer reps). They should be able to help you. My experience is that you do not want to use too much N when planting legumes and you definitely don't want to spread lots of N on extisting legumes (unless you wan the legumes to go away). They are N fixing and produce usable N for other plants. I believe I've read that the most important nutrient at planting is P. It is readily used by the seed when it is establishing. N is best for existing grass stands to bolster pruduction. With that said the 12-12-12 probably won't hurt you but may be better with a 5-10-10 (I think I used 0-20-20 for some seeding I did - grass/clover mix)
As far as the potash, didn't the lime take care of the pH. the potash is mostly for K (I thought). It probably does have some effect on pH though.
Again, consult with local "experts" and go with their advice.

Dan O.

Potash isn't normally used for pH control. The fertilizer recommendations that you receive are those for commercial growers to produce the most cost efficient crop (most $ back). You can add more or less fertilizer (within reason) and the crop will produce more or less than the economically optimum crop. If you apply an extreme excess you will contribute to leaching and runoff loses.

Dan O.

Pro-Line

I should have been a little more specific...The potash is due to a slight potassium dificiency, not pH...The lime should fix the pH, and the potash the K deficiency.

farm hunter

pro-line -

The 12-12-12 won't likely hurt - but might be a little more than you need - especially if you are adding potash too. potash = (0-0-60)

Keep on mind that 250 lbs of 0-0-60 = 150 lbs/acre of potassiium (k). This is a pretty decent quantity - even for poor soil. The 12-12-12 mixture is 12% each N-P-K. I don't think you would want to add any more K - it will only be wasted.

A little Nitrogen is sometimes usefull to "start" a crop - even clover (** only if residual N is very low). This is because even when properly innoculated, it takes a while for Nodules to grow, mature and allow the clover to fix atmospheric Nitrogen for its own use. If you soil sample indicates that you have more than 5-10 lbs/acre residule N - The adding more only "feeds the weeds".

Similarly - Phosphorus is can be applied in small quanties - (5-10 lbs/acre) to help with initial root growth. Even when soil samples indicate adequate levels of P - some people add a small amount to ensure the Pis availible in the root zone in sufficient levels. - Its like "cheap insurance".

lunchbucket

Your soil sample results should give the needed recommendations...

1sagittarius

My 5 acre hay field soil test recommendations for a 2.6-3.5 ton yield of alfalfa was ... 0 N, 65# Phosphorus (P2O2), and 175# Potassium (K2O) per acre. The recommendation was also for 2.5 tons/acre of lime to bring the PH from 6.4 up to 6.8.

To get close to those P and K recommendations would require 1400 lbs of 0-0-60, and 800 lbs of 18-46-0. These will be purchased in bulk from my local mill and spread with a tow behind spreader they rent for $10. Total cost ... under $300.

With clovers, you could get by with maybe 60-80% of the alfalfa recommendations.

Russ otten

The one factor that keeps me to thinking. That 50lb. bag is marked
12-12-12 when it really is 6-6-6. You have to put on 2 bags to reach that total. It's something that I consider when adding fertilizer. It may seem like you're getting the full strength, but that bag is only half strength. (Is this a marketing ploy?)

Russ otten

After a little thinking, I figured out what I was doing wrong. The numbers on the bag are percentage points, not weight. Thus, a 10-10-10 bag, 10% of 50 would be 5lbs. so there would be 15lbs. of nutrients. Now, there's 35 more lbs. of filler. I guess that it is used so that when spreading there is less chance of getting burn spots. Now I wonder, what is that filler? I would guess it is clay. What if they were to use lime as filler? Wouldn't that be an extra benefit when it was applied? (I know, guys, when a person starts to thinking, that's when he gets in trouble.)

psandhu

i'm pretty sure it's clay. i put some urea, dap, and potash from the coop in the tank of a sprayer. then i mixed it up so it was all dissolved, then sprayed it on a berm that i was planting grass seeds on. after 5 minutes the pump stopped pumping (12 volt, 1 gpm pump, 15 gallon tank). there was a clay sediment on the bottom of the tank. the levy was nice and red though, after i sprayed it. grass grew well, almost too well.