bolson32 wrote: ↑June 17th, 2021, 12:56 pm
Is there any concern on not having much slow-release at all? Would it behoove me to get some XCU or otherwise coated urea in one of the feeds?
There's no direct concern with this at all. The grass doesn't really care about the state of the nitrogen, and it'll start flipping forms as soon as it hits the soil.
There are some advantages (and disadvantages!) to organic nitrogen sources that you wont receive/suffer using this, but that's not a major issue. Starting slow is even an advantage in that a soil takes time to adjust to organics. You'll be building the bacteria and fungi in your soil that will handle these over time, without some of the headaches of instantly changing over to a full organic cycle.
Come fall, a lot of people spoon feed semi-weekly or even weekly, but with your time constraints, this isn't going to be you. Monthly is just fine, and the grass isn't going to complain about a pound of nitrogen a month delivered every month like clockwork in fall. That's absolutely fine.
It's also a bit of a fallacy that urea drops all at once. It really doesn't--release time is over about two days. Meanwhile, back at the ranch (the bacteria in the soil who released all the delightful urease that broke down the urea you dropped on the soil, because it doesn't hydrolyze quickly in water by itself and would take a couple years without them), they're happily sucking up the N you just tossed around, finding carbon sources (which you also generously provided in this), and reproducing like mad. Later on, bacteriophages, worms, and so on eat the bacteria, and excrete the nitrogen compounds (bacteria use far more nitrogen than any other being, it's a waste product in anything else). Which your grass happily consumes, unless another bacteria gets there first. In which case it loops around again.
Overuse of urea can be an issue if you're not adding the carbon sources to offset it; it'll flare off carbon compounds from the soil if material is removed (grass-cycling takes care of that problem on our lawns for the most part). So organic feeding adds that carbon right back, or mulching my gardens with 4" of bark (high carbon content). Or turning spent crop waste back under to decay into the soil. And so on...
You can do this anywhere. My gardens are fed both organically and synthetically. Once a month, May through August, they get a massive pounding of organic matter (Milorganite or soy, usually, 20-25 pounds per thousand square feet). Weekly, they receive a synthetic dose of urea as their nitrogen source (plus monoammonium phosphate, so there's a little extra N there, plus their P source, and potassium sulfate for K, a touch of kelp for minor and trace elements, a pinch of ferrous sulfate for iron, and just a wee smidge of sodium lauryl sulfate).
I get the advantage of slow, always-available nitrogen sources, plus fast sources of nitrogen at higher levels (and always available at the rates and as often as I feed). I spend most of summer setting my gardens in a permanent boom cycle. But I do have to replace the carbon lost by mulching it, and generally the plants at the end of the year end up in the lawn as part of the organic cycle there.