Corn farming question

I just had my first year of planting corn. Went fine but a dry year. I use a JD 7000 with dry fert and put out 500lb of 17-17-17. Which is the best way to plant corn?
17-17-17
19-19-19
10-20-20 with 30gl 32% at planting
10-20-20 with 30gl 32% over top later
and does it make a big difference if you use the planter to fertilize or just broadcast it when you plant?
The fertilizer system on this planter is wore slap out so wondering about rebuilding it or just leaving it off. See a lot of planters without any fertilizer on them.

I do soil sample, pretty decent land and just a maintenance app. of fert. Just my grandfather always put between 400-500lb under his corn.

100-80-80? I thought the sum of the numbers couldn't be greater than 100.

100-80-80 is total units not per 100 pounds.

dad always used 6-18-6, banded in row. (starter) then came back with NH3 when corn was about knee high. I would just broadcast 150 lbs of accual fertilizer before planting. if the soil is all up to snuff, around here they figger 1 pound of N, equals 1 bushel of corn.  

Seems to me, all of the methods you have mentioned are all a little low on N. As Shameless said, 1lb N per Bu yield potential, or even a little more.

That fact that you got 500 pounds per acre out of that planter is pretty amazing! Can't be that wore out, haha. But good grief, you were filling FREQUENTLY to keep it flowing right, about an acre per every two rows on your planter, right?

You are right, there are a lot of ways to plant corn and fertilize it. Some of the nutrients are more mobile than others, N is pretty mobile, so some of your N can be broadcast to lessen the volume that must go through the planter. Guys with no fertilizer on their planter at all either have an applicator or hire it done by someone with an applicator.

What I do, and I have a very similar setup, is I try to limit my fertilizer through the planter to approximately 300 lb or less. And I make up the rest of the N, and anything else like usually potash, with a spreader preplant. Analysis used is based on soil test.

Why are you guys broadcasting urea after the corn is up? Doesn't urea need to be either worked in, or heavily rained on almost immediately after application to avoid it breaking down and being wasted?
I would never broadcast urea when you can't work it in. Urea is the most expensive and least efficient application of N. Even when worked in, it washes away more quickly than anhydrous.

That's why guys sidedress and apply preemerge N. The preemerge gets the corn started with the N right where the corn can get to it. A few weeks later you sidedress, so when the starter is gone, the sidedressed N takes over and doesn't have time to wash away.

This is a generalization because I had a couple acres I didn't use any starter on, and used only Urea and AMS and it looks beautiful. I applied the Urea about 2 days before planting and ran a disk over it within an hour. That corn's beautiful, but it's generally not the most effective and least expensive way.

Shoot for the old rule of 1N per applied bushel like shameless said, but keep in mind you could need less depending on soil type. Muck has a lot of organic material that decomposes and creates N, so you get some free N. Legumes like soybeans should leave some N behind too, but I'm not sure how it really pencils out.

we found...using 98% uran, when corn was about knee high or sum less, dribble it between the rows. it'll soak into the dirt some, then the water in it will disapate until it rains, the rain will carry it down to the plant. then the plants get both water and fertilizer at the same time, putting it in the grow mode! and if it's dry, the plants are not stressing as much after receiving the fertilizer, searching harder for water to support it's faster growth! another plus to this is it takes less fuel to pull the rig thru the fields.

Allis Dave, I don't know if you were talking about me or not, but I don't broadcast urea post emerge. I do work it in preplant. If I put a little extra on, it's still cheaper than buying or renting an applicator and getting it put on at just the right timing.

NH3 takes time to convert to usable N also, just choices to be made.

Agrotain in the urea is supposed to help it have some staying power, but I personally haven't tried it yet.

I think LynnTN said they broadcast more urea when knee high

You're right, you have to know your ground. We have several small plots we do use urea on either because of rock, tree roots, or mucks. Sometimes the extra cost is justified. Sometimes you tear out more corn in odd shaped fields with the toolbar than you do good

topdressing urea is becoming more popular. you just need to do it with rain in the forecast. have heard of guys doing 200lb an acre or more. it will burn the corn a little where it comes in contact but its just cosmetic.   here urea was the cheapest form of N this past spring at $330 a ton.

We use Nutrisphere treatment on our urea, urea is the cheapest nitrogen we have here. We have it treated and do our best to spread when they are calling for rain. It does pay and you can see the difference from years past with no treatment.