The greatness of alfalfa meal isn't it's high N, but it being fairly well NPK balanced in a ratio plants use. Most plants use NPK in a 3-1-2 ratio or thereabouts and depending on who you ask alfalfa meal s 2.5-1-1 or thereabout so reasonably close to the ideal ratio for the majors.

Your math looks correct to me, but if you are only after nitrogen then skip alfalfa and use soybean meal instead. Protein is pretty standardized at around 48% which means 7.5% nitrogen and it is what I use for a lawn fertilizer. Unlike most grain meals, soybean meal spreads easily with a drop or broadcast spreader. The only drawback to it is that virtually all soybeans grown in the US are GMO (genetically modified). Not at all an issue when used as a fertilizer, it is more a political/philosophical issue where *you* have to decide what is OK and what is not.

If your goal is nitrogen, alfalfa meal pales in comparison to some other meals, but there is the GMO issue you may want to take into account. If your goal is a balanced nutritional meal then alfalfa meal is hard to beat.

BTW, you are being waaaaaay too anal about this. I have noticed that 5 or 6 posts at the top of the list are from you asking various related questions. I do not mind this, but it does reveal you have an NPK mindset and as a soil growing organic gardener you need to move beyond this.

Add copious amounts (2-3" per year) of compost/manure whatever generic OM and don't worry about it, it will take care of itself.

Just to make things easier what you are figuring is the amount of readily available Nitrogen in that meal, not the total amount of N that would be available because of the protein in the alfalfa. The amount of N you would be spreading is much greater than the readily available amount stated on the bag.

Justaguy-
Thanks. Yeah, I know I'm getting carried away with this... just kind of got carried down that road, really in an effort not to raise my phosphorous levels any more, while at the same time trying to utilize readily available materials. Also, trying to ensure that when I plant my winter garden and cover crop that have nutrients required to have it grow properly.... can't use cow manure right now because would need to wait until spring to till it all in. Then, I don't trust bagged composts, so that's kind of out of the question too. Anyway, it all added up to my multitude of questions. Hopefully I haven't rubbed anyone the wrong way with all the quesions.

So, you think that even with my high phosphorous levels, it will be OK to apply dairy manure & or compost at the rates you're suggesting, without messing up my soil chemistry?

Kimmser-
Nothing is stated on the bag other than the protein and fat content. Interestingly, I called the manufacturer today to find out if they had done any npk tests, and he gave me some info one of his clients had given him.

This particular alfafa meal is apparently is 5-1-2. I'm going to send a sample off to see if my results come back the same.

To help take some of the sting out of math when applying stuff, you can grab the calculators that I wrote for Microsoft Excel. If you don't have Excel they won't work for you (sorry).

I'm posted them previously on the soil forum here.

So, you think that even with my high phosphorous levels, it will be OK to apply dairy manure & or compost at the rates you're suggesting, without messing up my soil chemistry?

For the most part yes. Where I live phosphorus levels are also very high. This is due primarily to natural causes. When we add a source of nutrients to the soil there is a difference between adding what the plants require for the season and overdoing it where we end up with a surplus each year that continues to worsen the balance.

If you look at things such as tissue analysis this will reveal exactly what nutrients plants are using and in the amounts they are using them for normal growth. If you are adding things in the ratio and amount (approximately) that the plants are using then you really don't have much to worry about in terms of accumulation.

Also, nutrients come from different sources and release their nutrients at different rates. A rock powder for example will release slower, but last much longer than manure.

Also, a lot of the chemistry issues that take place in mineral soils either don't take place or their impact is reduced in soil-less growing media and organic matter is 'soil-less'. Simply put the chemistry just doesn't work the same because the properties of the media are not the same.

We have a lot more latitude with organic matter than we do with the soil in terms of nutrient amounts and pH.

Now, if you want the 'perfect' nutrient source, good luck :) The results of tissue analysis on veggies shows surprisingly little variance from one type of plant to the next. NPK in a 3-.5-2 or 3-.5-3 ratio is in line with what almost all plants actually use.

Here is a link to a study on the topic that may be of interest.

emyers: your math looks right. But I assume that applying stuff is just a stopgap. When you grow legumes in rotation you can stop worrying about the math once the rotation comes round -- like in 4 years. Regards, Peter.

justaguy-
Plant tissue analyis study copied to desktop. Will read it later... sounds interesting.

So, you pretty much are just trying to "maintain" your high levels, meaning you do regular tissue culture (somehow determining from individual plant cultures how much the entire garden is using?) to determine if plants are lacking anything and/or what they are using, and soil tests to back that up in an effort to see if soil levels are increasing/ decreasing?
I'm asking this because what I'm describing is the approach I was thinking about taking for my lawn. Was thinking that, "Eddie, since you've never fertilized your centipede grass before in 6 years, and the area that you water by your garden looks really good, and the soil by your garden is just like the rest of your yard, then even though your soil tests for your yard in both the good and bad areas say you are deficient in potassium and some other things, then maybe you really don't need to add anything anyway. Why not get a tissue culture done to verify that the grass in reality is deficient. Then, if something shows up deficient in the plant, add it to the grass. If not, just water the rest of the yard occassionally and forget about it."
Anyway, I suppose this could apply to excesses (mine and your P) also.
Am I on the right track here? Have no real basis for any of this, just kind of started thinking about what I would understand as the distinct roles of tissue culture vs soil samples.

The perfect nutrient source....
For getting things into INITIAL balance, cost and labor aside, wouldn't it be something that added organic matter that didn't tie up nitrogen but ONLY contained N P K as individual components within each ammendment?

Once things were in balance, you just apply something "balanced" as you say 3-.5-2 etc.... and a straight nitrogen source as needed?

All this is just for discussion obviously... I fully recognize that there are just too many variables for the perfect organic source.

Peter-
Yes, I've come to terms with the fact that I'm not trying to NPK things to death. All this is a temporary fix. I'm working out a plan for rotations and green manures, mulches etc, that will take me to the next level, just trying to come up with a good plan to take my particular soil there.
4 years to get there rotating, cover crops, and mulching eh?