Replacing Blood meal with Alfalfa meal in a soil mix

FredH

Well-Known Member
I use blood meal as my main source of nitrogen at 1/2 cup per cubic foot and that seems to be about right. However I would like to try to use Alfalfa as my main nitrogen source. How much of it per cubic foot of soil should I use to match it?
 

Weedvin

Well-Known Member
I use blood meal as my main source of nitrogen at 1/2 cup per cubic foot and that seems to be about right. However I would like to try to use Alfalfa as my main nitrogen source. How much of it per cubic foot of soil should I use to match it?
Thousands ✌ Alfalfa 2.5%N, Blood meal 15% N With alfalfa All the extras. Compost your alfalfa/blood meal.
 

FredH

Well-Known Member
What's your other fertilizers in the mix?
I go with 2 cups total mixing 1/2 cup each: fish meal, alfalfa meal, insect frass, high K organic commercial dry fert.

I would dare to go with 1 cup, but not more, at least on my first try.
I have been using the very simple Burn1's mix, 1/2 cup blood meal, 1 cup bone meal and 1/2 cup woodash for my K component. Have to say it has been working very well. Without composting it either.
 

FredH

Well-Known Member
Pretty heavy on the phosphorus there, and almost all in available form. For that reason I avoid it.
So far though I have had no phosphorous related problems, I sometimes only use half a cup but either way it works pretty good.
 

Weedvin

Well-Known Member
So 2 cups to start would give me a 10% level and work up from there?
No. Alfalfa contains 2.5-.5-3.0
If you use 1- cup or 50 cups it's the same analysis. I'd add steamed bone meal @ 4- cups/ bushel and blood meal@2- cups/bushel ( 1- bushel= 32 qrts. ) Moisten it ( it will get VERY hot) let it cool (7-10 days) use it in your containers freely or make tea ( after the 24 hrs soak use what's left in the tea bag in your containers.
 

FredH

Well-Known Member
So using Alfalfa meal like I have been using blood meal won't work? May try a test run.
 

Northwood

Well-Known Member
So far though I have had no phosphorous related problems, I sometimes only use half a cup but either way it works pretty good.
Well, bone meal has 15-17% phosphorus. It has comparatively little nitrogen (< 4%), and literally no potassium. It's extremely difficult to get a balanced soil using it. In order to balance that, you'd need a 40-0-30 amendment to add along with it. And then you'd only need a teaspoon or 2 per gallon of soil!

Excess N and K are harder to screw up, because excesses are easily lost through leaching (flushing) and N can be also lost to nitrification and volatilization. P is much harder to get rid of, and about your only recourse is to avoid using it for many years or decades, or have the soil removed and replaced.

Many organic backyard gardeners can go overboard on compost whose NPK is much more balanced when applied than bone meal (say 3-0.5-2 if made from plant material). When I mean overboard, I mean drastically over-compensating for what the plants can use in a single grow cycle or season. They can easily apply 10 times as much NPK derived from organic biomass than the crop plants would remove. Nothing bad happens in the first year, so they add the same the next, and the next. N toxicity may never be a problem due to natural loses, but the excess P stays there until their backyard becomes a toxic hazard years later where nothing will grow.

I suppose a balanced soil recipe isn't very important if you're doing a one-off grow and throwing away your amended medium every few months. However in my personal view, that's hardly "organic". Frankly if I had to do that, I'd just go back to hydro. It might be friendlier for the environment.
 

FredH

Well-Known Member
Well, bone meal has 15-17% phosphorus. It has comparatively little nitrogen (< 4%), and literally no potassium. It's extremely difficult to get a balanced soil using it. In order to balance that, you'd need a 40-0-30 amendment to add along with it. And then you'd only need a teaspoon or 2 per gallon of soil!

Excess N and K are harder to screw up, because excesses are easily lost through leaching (flushing) and N can be also lost to nitrification and volatilization. P is much harder to get rid of, and about your only recourse is to avoid using it for many years or decades, or have the soil removed and replaced.

Many organic backyard gardeners can go overboard on compost whose NPK is much more balanced when applied than bone meal (say 3-0.5-2 if made from plant material). When I mean overboard, I mean drastically over-compensating for what the plants can use in a single grow cycle or season. They can easily apply 10 times as much NPK derived from organic biomass than the crop plants would remove. Nothing bad happens in the first year, so they add the same the next, and the next. N toxicity may never be a problem due to natural loses, but the excess P stays there until their backyard becomes a toxic hazard years later where nothing will grow.

I suppose a balanced soil recipe isn't very important if you're doing a one-off grow and throwing away your amended medium every few months. However in my personal view, that's hardly "organic". Frankly if I had to do that, I'd just go back to hydro. It might be friendlier for the environment.
So a cup of bone meal in 7 gallons of soil is too much? I use wood ash for the K component and use my soil for two runs and then as bedding for my worms to make vermicompost from feeding them alfalfa generally. The the worm castings are used in teas. I don't feel I am causing any real environmental problems. Sometimes I use the leftover soil as a top dressing in the garden but mostly I use it for worm bedding. I have a lot of very healthy worms.
 

fivefour11

Member
bone meal it disolve very slow in soil and it doesnt burn plant like manures and high nitrogen organic fertilizer , I read that better to add 1 pound per 10 square in garden soil , wood ash high in potassium but it may make the soil ph more alkaline and cannabis going well with slighlty acidic soil , but the good side its a natural pesticide against some pests , for K I prefer to use sheep manure with adding liquid kelp meal frequently , and may it work half wood ash + half sheep manure for the K with little boost of small potassium ratio of kelp with its rich micro nuts
 
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OneMoreRip

Well-Known Member
I use blood meal as my main source of nitrogen at 1/2 cup per cubic foot and that seems to be about right. However I would like to try to use Alfalfa as my main nitrogen source. How much of it per cubic foot of soil should I use to match it?
Did you use it? how did it work for you?

I was going to use alfalfa pellets as only fert on some plants. See a lot of good stuff on it just looking for cannabis being grow with it as main fert.

get 50 pounds for 15 bucks at feed store near me, wonder why not more people using it
 

lakesidegrower

Well-Known Member
Did you use it? how did it work for you?

I was going to use alfalfa pellets as only fert on some plants. See a lot of good stuff on it just looking for cannabis being grow with it as main fert.

get 50 pounds for 15 bucks at feed store near me, wonder why not more people using it
Lots of people do use exactly that, but they just aren’t on here talking about it. It also doesn’t come in a fancy package with marketing behind it lol

@Northwood knows what he’s talking about, it’s great advice to keep it simple with your soil build and focus on sources of N and K like frass, alfalfa and kelp, don’t add a ton of bone or blood meals (I personally go with fish bone meal as the only added bone meal in my soil mix to incorporate P ), and then top dress for a P boost in flower if needed.

Don’t get me wrong, they are great amendments that people use and love, but my advice would be to use as a top dress in flower, or buy a balanced, pre-mixed dry amendment like a 4-4-4 so you can add in the P ‘safely’ in an already-balanced mix. Remember that you can’t take out what add to your soil build, but you can always top dress or water in what you need.
 

OneMoreRip

Well-Known Member
only need alfalfa pellets and medium, whole way through, from what I’m gathering.

average npk 2-1-2 which is perfect for cannabis according to nasa’s weed scientist

not really into putting animals into my plants lol

I got some other organic ferts (dr earth), and just about everything in the is some sort of animal consumption byproduct which is kinda gross gonna give them away hopefully.
 

lakesidegrower

Well-Known Member
only need alfalfa pellets and medium, whole way through, from what I’m gathering.

average npk 2-1-2 which is perfect for cannabis according to nasa’s weed scientist

not really into putting animals into my plants lol

I got some other organic ferts (dr earth), and just about everything in the is some sort of animal consumption byproduct which is kinda gross gonna give them away hopefully.
Yea some people do just that - I’d toss something else in there - either kelp or insect frass
I’m looking through my notes.. can’t find what my NPK target was, but I did the math on determining what my overall NPK would be with different amount of different supplements and added half and cup of this took at half a cup of that to get to what I thought was a good overall NPK for my soil build. I spent way to much time on it but I was into it lol

I don’t really care about animal products being in my soil but my go to is marine products like fish/seaweed/kelp over blood/bone meals.
 

OneMoreRip

Well-Known Member
I just hydrated a bunch of alfalfa pellets. Easy to grind up after sitting in the sun. View attachment 5012604
have you used it as you medium , if not what is max % you like to use?

I was considering 50/50 pellets/vermiculite on a plant or 2 to see what happens

heard of people growing in straight cow manure (aged), I’m pretty sure so I think they can handle alfalfa
 

JHake

Well-Known Member
I just hydrated a bunch of alfalfa pellets. Easy to grind up after sitting in the sun.
Done the same few days ago. Much easier to use in that form.

heard of people growing in straight cow manure (aged), I’m pretty sure so I think they can handle alfalfa
Alfalfa is and can get very hot at first! Be sure to let it cook. Normal ratios for nutrients are 1-3 cups per cu ft of base soil.
 
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