I use only organic fertilizer for my entire garden, but I never use commercially bagged fertilizers.

Microlife has 20 different products. You'll have to be more specific about which one you're looking at.

But here's the thing about organic fertilizer: they all contain a mix of ground up nuts, beans, seeds, and grains as the source of nitrogen. There are a couple exceptions and one is the Microlife line which relies on seaweed for the source of protein (the nitrogen source). The theory of organic fertilizers is that they feed real food to the microbes living in the soil. Once those microbes are well fed and watered, they will produce real plant food just like that supplied artificially with chemical fertilizers. The biological process to create the plant food takes about 3 weeks which is why organic fertilizers are referred to as 'slow release.' Actually they are not slow release - it just takes 3 weeks to make the fertilizer. Then they provide a natural release not affected by osmotic pressures like chemicals are.

If you look at the ingredients on bags of commercial organic fertilizers they will list soybean meal, alfalfa meal, cottonseed meal, cornmeal, corn gluten meal, and sometimes wheat flour, flax, and others. They might also contain animal byproducts like feather meal, poultry litter, and seaweed. All these things are food for the microbes providing protein. I buy alfalfa pellets (aka rabbit chow) and ordinary corn meal at my local feed store for $15 and $10 respectively for a 50 pound bag. The application rate of most all organic fertilizers is 15 to 20 pounds per 1,000 square feet. So you can DIY like many of us do or you can buy the Microlife or other commercial fertilizers and pay about 7x more per 1,000 square feet.

I bought some on sale at my local big box store. I did not like it. It sat on the lawn for a long time, did not work itself into the soil very well. Not much effect. I could have just as easily spread compost with less cost. If it is grass, I say go with the right timing, concentration and application rate of commercial fertilizer if you want lawn grass effects. I don't have much lawn, mostly mulched beds. Grass lawn is rather unnatural to begin with so I don't see the benefit in spending extra money for something "organic." YMMV. I do use organic grub treatments, (milky spore and nematodes). I find them to be far superior to the conventional pesticides.

Compost at less cost??? Here's more data.

The application rate for compost is 1 cubic yard per 1,000 square feet. In my neighborhood, compost costs $45/cubic yard plus $50 delivery bringing the cost of compost to $95 per 1,000 square feet. Whereas a bag of cornmeal costs $10 and covers 2,500 square feet. Cost of corn meal is $4.00 per 1,000 square feet. And if you've ever spread a cubic yard of compost, you'll never want to do THAT again.

Here's a picture demonstrating how organic fertilizer works.

Thanks to mrmumbles for posting that picture here about 11 years ago. The grass is zoysia. He dropped a handful of alfalfa pellets on that green spot in mid May and took the picture in mid June. Yes, it takes 3 full weeks for organic fertilizer to work, but it works. The pic shows the improved, color, density, and growth very clearly.

If you have problems with an organic fertilizer getting down to the soil, simply drag a hose across after you applied it. Organics do not need to be watered in like chemical fertilizers. No harm will come if you don't do it at all, but they do need water for the microbes to "activate" and start decomposing the fertilizer. With alfalfa pellets (rabbit chow) they need to be moistened, not flooded, and one day later dragged with the hose to get them down to the soil.