[PureHarvest]

So alfalfa pellets have 3% N.
This means that there are only 1.2 lbs of actual nitrogen in that 40lb bag.
Than means you are paying $16.66 per pound of actual nitrogen.
Not a big deal for a small area, but relative to large scale that is expensive.
The chicken manure based stuff I have is $3.13 per pound of N.
As far as soil conditioning, yes you are adding carbon/organic matter with the pellets, but you would have to add a lot to a given area to make a difference.
This is fine if you are planting a few tomato plants in a short row, but if you are making beds of any decent length, your 40lb bag is going to disappear faster than can cover the beds at a rate that will amend your soil. Fertilizer wise, still doable, but soil conditioning wise, not really a needle-mover because it is just not that much biomass.
Lets say you want to prep a 3' x 50' bed that you will plant 3 rows of garlic in.
That is 150 square feet. In acre terms, that is .0034 of an acre.
The rec for nitrogen per acre for garlic is 100 lbs for the crop, with all 100lbs of that coming from a pre-plant application if it is a slow-release form like your alfalfa.
If you use a soluble form, you would do that application in the early spring, split into multiple apps over a couple months ideally.
So, lets say you want to put down 100lbs before you plant.
100lbs x .0034= .34 lbs of actual N needed.
But your pellets are only 3% N.
So, .34 / .03= 11.33 lbs of pellets to fertilize a 3' x 50' bed with a rate of 100 lbs per acre.
So, how big and how many beds are you planting?
Ideally, you add compost or do cover cropping the year/years before you plant to amend and condition your soil, and look at organic fertilizers as, well, just fertilizers, not major soil conditioners.
Remember, the soil is biological, physical, and chemical.
Adding organic fertilizer will change the bio and chemical, but probably not the physical by itself. Changing any one of the component does affect the others, but a holistic approach to changing all three over time is a multi-year process.
I know that does not help this year, but if you can look at where you will plant 2 years from now, you can start to look at cover crops in spring and fall that will alter your soil positively. Biomass above the ground is not what you are chasing. It's what everyone sees, so it is over-rated. It's the bio-mass below ground via roots that matter. Those roots interact with microbes, sink exudates and carbon to feed the rhizosphere and physically penetrate deep into the clay layers, opening up channels for air and water exchange.
Look for mixes that will give you fiberous (shallow) and deep penetrating (more chord like).
Permanent covers like grass and clover are good too but can provide good habitat for wireworms (bad).
The areas I will move into in the future have been in tall fescue and clover for 4 years. Permanent cover is always one of the best soil health builders.
Currently, I kill that off and plant into those areas.
But, the wireworms. I have too much bulb damage from them.
So, brown mustard is the crop I am looking at to move from my tall fescue/clover pasture.
This means that I need to tarp off next fall's area at the beginning of next year so that I can plant mustard there in early spring. Then come fall, I just need to till in the dead/dying cover of mustard and plant into it.