# How fast will it leech?



## jsams22 (Apr 20, 2021)

Just sprigged a new Ultradwarf Putting green. I put down a water soluble 20-20-20 at 1#per 1k.

My question is, with a sandy loamy soil, watering it every hour for a couple minutes, how quickly will that 1# leech out of the soil? We are going from 70s to mid 90s this weekend, so will have to step up the watering to protect sprigs. Just wanted to make sure the sprigs are getting use of it before the water leeches it away. Thanks!

Edit: my CEC (Cation Exchange Capacity) was 7.3meq/100g


----------



## Virginiagal (Apr 24, 2017)

It depends on your cation exchange capacity (CEC ). If it's quite low, like 5 or under, it would be best to spoon feed nutrients. Instead of doing 1 lb every month, do 1/2 lb every two weeks (during appropriate times to fertilize).


----------



## jsams22 (Apr 20, 2021)

On my soil test its showing my CEC (Cation Exchange Capacity) is 7.3meq/100g. But that was for my yard. For the putting green area, its the same soil, just I added in a couple tons of sand to a 500sq ft area and cultivated it in.

I am planning on spoon feeding at .25# N per week, but I still want to get some P and K down. Just trying to get a general window of how often I supplement.


----------



## Virginiagal (Apr 24, 2017)

Since you're mixing sand with a soil somewhat low anyway in CEC, spoon feeding the P and K every two weeks would make sense. How are you doing the .25# N per week? If you do 20-20-20 to get a half lb each of P and K, it also gives you a half lb of N. Maybe you can find phosphorus only and potassium only fertilizers?


----------



## Mightyquinn (Jan 31, 2017)

I doubt those sprigs have very deep roots so I would guess that once the fertilize is washed off the leaf it would be difficult for it to uptake anything after an irrigation run.


----------



## ROJ_3030 (Sep 28, 2019)

This is very interesting based on some recent theory I'm putting together. I also have quite a low CEC at 8.2. What I noticed recently was after a fert application of 1/2lb N (AMS), 1 lb. P (TSP), and 1 lb (SOP) I had a noticeable response in both color and growth rate as to be expected. I then ran the irrigation through several deep soaking 1/2" cycles to keep up with ET. as we've been extremely dry lately. Within two weeks, I started to lose color and growth slowed down. The grass was looking sickly like it needed to be fed again. 3 weeks after that application, I went out with a custom blend triple 11 at 3/4 lb. /M and my color and overall health came right back. This custom blend used the same AMS, TSP and SOP.

Is it normal to leech nitrogen within 2-3 weeks with a fast release source and cause a visible change in turf?


----------

