True the vast majority of people use chemical fertilizers, and chemicals are easier to handle, but I disagree about the cost and effectiveness. If you're comparing chemical ferts with compost, then everything is 7x cheaper. With organics we don't normally talk about NPK. The only thing that's important is protein content. The bags are labeled with NPK as a requirement for sale in the US, but protein content would be more appropriate for organics. Bags of alfalfa (and corn and soybean meal, etc.) are labeled with protein content. Even after converting protein to nitrogen, the numbers look off. Fortunately organic fertilizers are a biological product and not a chemical product, so the NPK comparison is not apples to apples. Most organic fertilizers work just fine.

More effective is in the eye of the beholder. Here's a picture showing the effectiveness of alfalfa pellets.

Alfalfa pellets (rabbit chow) run about $12 for 50 pounds at feed stores all around the country. Instead of carrying 2 bags around with me, like j4c11 apparently does, I open one bag and put it in my wagon. Then I have a 2-pound coffee can that I scoop it out with. I hand scatter 2 pounds over a 10x10 foot area (100 square feet).

As for timing you can apply any time, but we generally talk about three applications on Memorial Day, Labor Day, and Thanksgiving. If the lawn looks yellowish earlier in May, go ahead and apply earlier. The grass is going to grow fast once it awakens in the spring, so you can just sit back and mow it every week. Your grasses should be mulch mowed at the highest setting.

The eternal conflict continues!

Well but grass has specific nitrogen requirements in pounds per square kilofoot per year, so if we have a certain goal of pounds per square kilofoot per year to achieve, then I think it's fair to compare in those terms.A 50# bag of alfalfa for $12 at 5% nitrogen results in a cost of $4.8 per pound of nitrogen. A 50# bag of urea for $19 at 46% nitrogen results in a cost of $0.80 per pound of nitrogen, which means it's about 6 times cheaper. I guess I was wrong, 7 times is when compared to Milorganite. Still, significant cost difference. I think speed and precision matters when measuring effectiveness, if you put down alfalfa it's going to decompose at some point and provide the nitrogen - when exactly, who knows - whereas with granular, you can time the application more effectively, you know exactly what you're getting and when. Also, alfalfa is not going to break down very well unless it's warm. Which is why I'm sure you put down urea as winterizer and not alfalfa pellets.

Organics like alfalfa don't simply degrade into nitrogen though, there are other compounds produced during the decay process that feed all kinds of critters, fungus, bacteria, worms, etc. It's just not an apples to apples comparison because nitrogen alone doesn't fill all the plants needs.

I usually fertilize every 5 weeks for lawns that are in bad shape. After fixing the soil (usually takes 5 years), I never have to fertilize again

Like eating foods rich in probiotics (a good yogurt for example) helps the bugs in one's gut, the same can be said for feeding the microherd of a lawn. Is that correct? If that's right then alfalfa would be better than a synthetic fertilizer for the overall health of the grass. Does Milorganite feed the microherd?

I don't think the analogy is accurate. You can grow plants hydroponically in sterile water with just NPK and micronutrients and they will grow very healthy. Thus, as long as the plant is provided water, light and the nutrients it needs, it couldn't care less about the "microherd".

Does feeding the herd help lessen thatch, though? Now, that I think more about it, I do have a house plant that's in just water and has been for at least a year and it does flourish....

I have very little thatch and add no organic feedings to my lawn. The microherd will always be proportional to the amount of food available, and so I guess I have exactly enough microorganisms that can be sustained by the grass clippings. Which is a more balanced approach imo than an artificially inflated population which without constant food input will crash and is therefore unsustainable.

I'm literally researching mulching mowers right now. We have a lawn mover with the bag now. Which mulching mower is recommended? We will be mowing a 5 thousand square foot lawn.

Most 21" push mowers will mulch by simply removing the bag and closing the side discharge. Basically no way out for the clippings except back down into the lawn.

And the clipping will be small enough? So there would be no need for me to buy a different lawn mower? Should I at least get a mulching blade for my current lawn mower? Thanks for taking the time to answer my questions...

Well, in theory you should only cut 30% of the blade length any time, so clippings shouldn't be longer than an inch even without the mulching. But yes, they will get chopped up enough. I use a standard blade to mulch, works just fine - I do sharpen it well though, try that before you get a mulching blade. I tried a mulching blade and didn't see much difference. As long as your current mower will close both side discharge and bag chute it will work. Most mowers do.

BTW, I leave clippings on the lawn even when I side discharge.

Totally depends on the budget. Toro & Honda are kind of the Ford & Chevy of quality mowers, but there's a million smaller brands out there too. If you go cheaper than $350 or so, I might buy the total coverage warranty if you're not handy.

I purchased a self propelled Craftsman about 3 years ago on black friday for about $180. A few days later, went to Lowe's and saw the exact same mower, only in orange and with a Husqvarna logo on it for $400. Absolutely identical down to the nuts and bolts, obviously made by the same company, probably MTD. Pays to do a little bit of research.