Spreading Fertilizer

A while back when I was talking to my local fertilizer/lime dealer. This is what he does for a living. He had made a comment that when he was in meeting with his supplier, the supplier told him it was better to spread fertilizer right after a rain. They stated more nutrients went into the ground than when it was spread before a rain. This makes sense if it is a down pour but a light rain doesn't make sense to me but I'm not the expert.

What do you think? Don't blame me I'm just the messenger.

Silly. Show me the science. You won't find any, and if you do, the ultimate outcome is inconsequential.

They have a point depending on what you are applying. Nitrogen, especially Urea or any other quickly released form of N tends to either gas off leach down out of the root zone or run off before the crop can benefit from it if there is a heavy rain. But so do phosphorous and potassium, just not as quickly and the soil in most cases already has P & K in it. Nitrogen though, unless in a slow release form can get the heck out of Dodge before the crop can benefit from it. different crops will have different requirement for nutrients. There are so many variables that a blanket statement like that is both right and wrong depending on the situation. I think fertilizer before a rain is ideal if you get a light to moderate rain, but that's out of your control in most cases.

Leaching doesn’t happen that fast and if it does someone needs to tell all the farmers who fall apply.

Yes if it is a down pour you could potentially loos anything on the surface, if the water does not infiltrate the soils. Also have to take into account any slopes.

Applying after a rain on wet soils does something different and much worse in my opinion than loosing a little bit of nutrients. Driving on wet ground causes compaction way easier than driving on dry ground.

Also fro unincorporated surface applied nutrients how else is it supposed to get into the root zone? What happens the next time it rains? Sorry but in my opinion the person who said this is all wet.


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Doesn't N burn leaves when applied to wet foliage?

Tap said:

Doesn't N burn leaves when applied to wet foliage?

Click to expand...

It very well can.


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I think your guy has it backwards....if it doesn't rain soon after fertilizer spreading, you could loose some due to evaporation.

https://www.noble.org/news/publications/ag-news-and-views/2009/may/nitrogen-losses-from-urea/

Assuming youre talking about N, you either want a good soaking rain ASAP after spreading or you want it to be as dry as possible until you get a soaking rain, a small amount of rain can desolve the N and then it starts to gas off very quickly.

Wet leaves are a no go as well.

BUT you can have some soils that the N will go through the profile pretty quickly, it depends on the soils and what kinds of rain events you get. I farm some beach sand that can leach a significant amount of N through it if we get heavy rains, which is fairly rare but we still hedge against this by spoon feeding the N as much as possible, only putting out what the crop needs, and using N stabilizers. Whereas the yellow clay we farm leaches almost 0 N, and we can count on most of the carryover to be there next year.

Remember at the end of the day, he makes his living from selling you fertilizer, so take what he says with a grain of salt.

Guys..I'm with you about spreading just before a rain to incorporate the N into the soil. Farmers have been spreading before a rain for many years with good results. I have always and always will spread right before a rain. Corporate will always try to make money one way or another and the little guy is the one who pays their bills.

Not surprised that the person who "does that for a living" doesn't know what they are talking about---That's just standard operating procedures now days. When I run across people that are giving bogus information I stop doing business with them.