Anyone have a recipe for making liquid fertilizer from stock chemicals like potassium nitrate?

[Meadowlark]

Don't waste money of over priced $5 boxes of plant food.

Go to a Farmers supply store you can buy any type fertilizer $20 per 50 lb. bag. Most of the plant food in a bottles and 5 lb. boxes and bags cost $20 also. In TN we have, Farmers Co-op and TSC = tractor supply. I buy, 21-0-0, 46-0-0, 6-12-12, 15-15-15, 0-20-20,

Each plants need its own type food. Onions need 21-0-0 for 6 weeks then 0-20-20 for 6 weeks.

Potatoes and tomatoes need, 15-15-15 for 1 month then 6-12-12 for a month, then 0-20-20.

Corn needs 15-15-15 and 46-0-0 a week before planting seeds then 46-0-0 when corn is knee high, again when plants are 4 ft tall, again when ears have silks.

Beans, strawberry plants and garlic like, 15-15-15.




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Please tell me how you know exactly what plants need what fertilizer without knowing what nutrients are already in the soil?

For example, you say onions need 21-0-0 for 6 weeks...how do you know what nitrogen is already in the soil? If it is above 30 ppm, do you need more nitrogen for 6 weeks?? Does it matter how much?

So, corn needs 46-0-0 added before planting...how do you know what level of nitrogen is already in the soil? Is your point that no matter what your soil may contain, it still needs 46-0-0 nitrogen if I plant corn? How much is enough? How much is too much?

 

[Horseflesh]

All I know is someone said my bay tree didn't look green enough and needed fertilizer. Apparently I need a Ph.D and a soil test to take next steps!

 

[gary350]

Please tell me how you know exactly what plants need what fertilizer without knowing what nutrients are already in the soil?

For example, you say onions need 21-0-0 for 6 weeks...how do you know what nitrogen is already in the soil? If it is above 30 ppm, do you need more nitrogen for 6 weeks?? Does it matter how much?

So, corn needs 46-0-0 added before planting...how do you know what level of nitrogen is already in the soil? Is your point that no matter what your soil may contain, it still needs 46-0-0 nitrogen if I plant corn? How much is enough? How much is too much?

There are 100s of research studies online. There are 100s commercial farmer videos online also. Farmers that plant 10,000. acres every year for 50 years know what plants need to grow a good harvest without soil tests every year. If you put fertilizer in your soil it will not stay there very long rain washes it away, nitrogen is gone first. Research studies know onions need high nitrogen first to grow as many leaves as possible next switch to high P&K to get large bulbs. I live at 14.3° longitude my longest day is 14 hrs 20 min, on June 21. When my day length becomes 12 hrs long onion fertilizer need to change from nitrogen to P&K. Ammonium sulfate is 21-0-0 it is slightly acid onions like acid soil, potatoes and blueberry plants do too. New gardeners should get a soil test but if you have been growing a garden for 50 years you know what works in your location, your weather, rain, wind, cold, hot weather, and your soil. We have too much spring rain in TN it washes away fertilizer and calcium. I have learned from experience my, tomatoes, melons, peppers, squash, cucumbers, etc, will all get BER = Blossom End Rot every summer so I give plants lime once a week to prevent BER. Calcium once a week may be too much but its better than BER. Nitrogen does not stay long in the soil research tells commercial farmers in the corn belt the correct way to fertilize no soil test required. 46-0-0 Urea fertilizer is slow release fertilizer it will not release at all until it comes in contact with calcium and rain water in the soil. You can read research studies online that say, tomatoes like 6-12-12, beans like 15-15-15, corn likes 46-0-0 etc. It is better to feed plants too much P&K than not enough.

I have a cousin that farms 2000 acres of corn in southern Illinois every year. I have another cousin in central Illinois that also plants 2000 acres of corn every year. They both take advise from research studies but they mostly go by what they know that works for them. 32" row spacing, 5" seed spacing, plant north south rows, calcium and fertilizer when planting seeds. They ration fertilizer, too much fertilizer is wasted money and not enough fertilizer is lost money with a smaller crop. The home gardener has the luxury of giving plants too much fertilizer, too much water, too much lime, if a farmer gives 2000 acres of corn too much fertilizer that could be $20,000. lost profit. If the same farmer does not give plants enough fertilizer that can also be $20,000. lost profit.

I fertilize according to what I know works for me. I read the research studies to get ideas. What works for me may not work for someone else in a different location, different weather, different soil, what works for them may not work for others in other locations. We need to know what each plant likes best and what plants don't like.

 

[big rockpile]

Go to Garden Like A Viking.

He has many videos on making Fertilizer.

He is mainly into no till gardening but has many other things to check out.

big rockpile

 

[orguiframun1977]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen—then just weigh out the right amount of chemicals to hit that target. For example, with something like 20-20-20 fertilizer, you’d need about 2.8 g per gallon of water to get 150 ppm of nitrogen.

 

[Horseflesh]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen....

That is exactly where I need to start. If I know the target PPM I can figure out the amounts. That is exactly how I manage ferts in my aquariums.

But what are the right PPM values for a generic "my bay tree is turning yellow" fertilizer?

 

[Meadowlark]

But what are the right PPM values for a generic "my bay tree is turning yellow" fertilizer?

The soil test lab I use goes by the following PPM ranges as optimal for vegetable gardens:

Total Nitrogen = 32-60
Phosphorus = 8-20
Potassium = 38-80 (dependent on cation exchange capacity )

 

[YumYum]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen—then just weigh out the right amount of chemicals to hit that target. For example, with something like 20-20-20 fertilizer, you’d need about 2.8 g per gallon of water to get 150 ppm of nitrogen.

I'm proud to see someone knows the math to do that.

1) A gallon of water weighs 3783 g.
2) Divide that by a million which equals 0.003783 g, which is the weight of 1 part per million in grams.
3) 150 ppm * 0.003783 = 0.56745 g to reach 150 ppm, but wait that is a 100% product and you have a 20% product.
4) 0.56745 / 0.20 = 2.83725 g. So 2.8 grams of that product per gallon is 150 ppm N by weight, or P or K since they are also 20%.

 

[YumYum]

That is exactly where I need to start. If I know the target PPM I can figure out the amounts. That is exactly how I manage ferts in my aquariums.

But what are the right PPM values for a generic "my bay tree is turning yellow" fertilizer?

There simply isn't a one size fits all answer.

For one, it depends on what you are growing in. Soil vs a soilless potting mix will handle different numbers since a potting mix can flush itself out while soil holds onto certain nutrients and can build up over time.

Number two, it depends on what is already in the soil and what you are fertilizing it with. You would use less with a synthetic fertilizer than an organic since it will be available right then but you would add more smaller doses. With an organic fertilizer you could add more ppm of N since it takes some time for the microbes to break down the nutrients into plant available forms.

There are also other factors that affect nutrient uptake such as daylight length, light strength, number of microbes in the soil (organics), and air temp or soil temp which in turn the plant pulls more or less nutrients out of the soil. These are all in relation to plant growth speed.

 

[Horseflesh]

There simply isn't a one size fits all answer...

I will settle for "one size fits somewhat."

Number two, it depends on what is already in the soil and what you are fertilizing it with...

The plant has never had anything but sunlight and water and whatever is in the potting soil.

My goal is to mix a general purpose fertilizer from bulk macros: KNO3, K2SO4, KH2PO4.

I understand it is not possible to optimize fertilization without information that I don't have but I would think it is possible to select (and then create) a fertilizer that is safe and beneficial even with no soil data. But maybe everyone in the garden store is doing soil tests before they buy that bottle of Miracle-Grow. I have no idea.

If it is not possible to make or even buy a reasonable general-purpose fertilizer that can be used without any soil tests, then I guess my bay laurel isn't getting fertilized!

 

[orguiframun1977]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen—then just weigh out the right amount of chemicals to hit that target. For example, with something like 20-20-20 fertilizer, you’d need about 2.8 g per gallon of water to get 150 ppm of nitrogen.
Also, while I was hunting for chemicals, I came across info on sodium lauryl sulphate price. If you ever need bulk chemicals, it’s good to compare prices because it can save you some cash if you’re doing this often.

 

[Meadowlark]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen—

The soil test lab I have used for years says above 60 ppm total nitrogen is HIGH. 150 ppm would burn most of my garden plants.

What are you growing at 150 ppm nitrogen?

 

[YumYum]

What I do is figure out how much of each nutrient I want in my mix—like 150 ppm nitrogen—then just weigh out the right amount of chemicals to hit that target. For example, with something like 20-20-20 fertilizer, you’d need about 2.8 g per gallon of water to get 150 ppm of nitrogen.

The soil test lab I have used for years says above 60 ppm total nitrogen is HIGH. 150 ppm would burn most of my garden plants.

What are you growing at 150 ppm nitrogen?

@orguiframun1977 figures are in units of weight per lb of water in which you are watering the soil or some other media with. @Meadowlark, you are going buy units of weight per lb of soil. They don't exactly cross over the same although the math is the same.

If you water 100 lbs of soil with 100 lbs of water with 150 ppm N the concentration changes within the soil since the water will have spread out into a larger volume because the soil particles are in the way. The soil would actually test less than 150 ppm N if it had none to start with.

Something else to consider is that soil will hold onto some and let others leach out while peat moss will leach most if not all of the fertilizer out so you would fertilize soil less frequently than you would a potted plant.

 

[Meadowlark]

@Horseflesh was addressing " liquid fertilizers for potted plants" as I assume was @orguiframun1977.

150 ppm sounds very high to me and not something I would put on potted plants...but that's just me.

What Is Parts Per Million (ppm)? How Is It Calculated? | Atlas Scientific

Parts per million (ppm) is a unit typically used to express the concentration of a substance in a solution or mixture. However, ppm can also be used to determine parts and quality in the automotive…

atlas-scientific.com

 

[Meadowlark]

By the way and just as an aside, there is an excellent 1/2-hour weekly program carried on the Rural RFD network called " Ag PHD".

They routinely get into the specifics of these issues...although the target audience is usually big farms of thousands of acres. It can get very technical.

I might add they completely dispute the notion that soil tests are not needed once you understand your soil.