How much fertilizer is too much when feeding mangoes

[mangoba]

A Mango growing publication from University of Florida recommends a total of 1.5-3 lb of 8-3-9-2 fertilizer for example. (680-1360 g)

My growing season is about 6-7 months (~26 weeks) and my fertilizer strength is twice of the mentioned one 14-6-20-4 so let's just assume that I would need about half of the amount which is 340-680g

I prefer to fertilize every time I water a seedling, which is around 10L each week.

When we do the math we get a dose of 13-26g in each watering which is 1.3-2.6g/L.

Should I be worried about that much fertilizer in the irrigation water? (I'm using the most expensive fertilizers with no chloride and mostly rain water)

I have very calcareous sandy soil poor in almost everything.

[spaugh]

You might want to invest in a TDS (total disolved solids) meter and check how many ppm your mixture is.  You probably dont want more than 150 or 200ppm if you are doing it every watering and the plants are in pots. 

A good rinse with rain water every now and then to cleanse the buildup out would be good too.  Plants dont like it when the roots are sitting in salt buildup in the bottom of a pot. 

[mangoba]

You might want to invest in a TDS (total disolved solids) meter and check how many ppm your mixture is.  You probably dont want more than 150 or 200ppm if you are doing it every watering and the plants are in pots. 

A good rinse with rain water every now and then to cleanse the buildup out would be good too.  Plants dont like it when the roots are sitting in salt buildup in the bottom of a pot.

Thanks Brad. I missed to mention that these are in ground seedlings.

My rainwater is already at 176ppm which is 0.176g/L.

I know you meant 200ppm for the total but Let's assume 200ppm of added salts. 200ppm = 0.2g/L.

If I follow that rate throughout the growing season I would end up with just 0.2*10*26 = 52g about 10 folds less than UF recommended rate?

[achetadomestica]

My smaller mangos I apply 8-4-8 Diamond R granular with micros. I only put a couple
small scoops every first of the month. I am amazed at how dark green the leaves
are. I have a couple larger trees that produce and I haven't fertilized them in a
couple years and they are dark green also. Mangos don't need allot of fertilizer
in my yard. I also apply Southern Ag citrus foliar spray a couple times a year.
If you watch the leaves you should be able to figure it out.

[spaugh]

You might want to invest in a TDS (total disolved solids) meter and check how many ppm your mixture is.  You probably dont want more than 150 or 200ppm if you are doing it every watering and the plants are in pots. 

A good rinse with rain water every now and then to cleanse the buildup out would be good too.  Plants dont like it when the roots are sitting in salt buildup in the bottom of a pot.

Thanks Brad. I missed to mention that these are in ground seedlings.

My rainwater is already at 176ppm which is 0.176g/L.

I know you meant 200ppm for the total but Let's assume 200ppm of added salts. 200ppm = 0.2g/L.

If I follow that rate throughout the growing season I would end up with just 0.2*10*26 = 52g about 10 folds less than UF recommended rate?

maybe just start with 200ppm of salts, then start working it up slowly if the trees are responding well.  2000ppm of salts every time you water sounds like too much for a plant with somewhat low vigor.  Thats the amount of fertilizer a very vigorous tomato plant would use. 

How much rainfall are you getting?

[mangoba]

Thank you, I actually get almost nothing during the season, I just collect few cubic meters during the rest of the year.

achetadomestica your soil might be rich already, mine is a disaster.

[Aiptasia904]

Thanks Brad. I missed to mention that these are in ground seedlings.

My rainwater is already at 176ppm which is 0.176g/L.

I know you meant 200ppm for the total but Let's assume 200ppm of added salts. 200ppm = 0.2g/L.

If I follow that rate throughout the growing season I would end up with just 0.2*10*26 = 52g about 10 folds less than UF recommended rate?

Your rainwater is 176 ppm tds? What are you adding to it? Rainwater is better than distilled and should be 0 ppm tds. If you're showing a tds reading with sequestered rainwater make sure you're calibrating your TDS meter.

Use what you have as far as fertilizers you're using, but a lot of these issues can be solved by using organic solid fertilizers such as Espoma's chicken poop based fertilizers. They make a mango mix and it will continue to dissolve and feed your mangoes with every rainfall and watering when used as directed as a top dressing. No math needed.

Newly sprouted seedlings won't need any fertilizer at all for the first two months if you're using a good quality potting/sprouting mix. You're correct in using about half the amount of the fertilizer you are using when you fertilize. I wouldn't worry so much about feeding fertilizer with every watering. You should be feeding your mango seedlings about every month and a half to two months during the season once they've depleted available nutrients from the seeds themselves and in their first soil and not at all in the winter. Let rainwater do your soil flushing.

[pineislander]

Usually the rain water collector surface (roof) builds up some dissolvable minerals.

[achetadomestica]

My soil is white sand.
Mangos need very little fertilizer. They do love water
You may be making this too complicated?

[mangoba]

My soil is white sand.
Mangos need very little fertilizer. They do love water
You may be making this too complicated?

That's exactly what I'm thinking, how much roughly do you give them and do you have an idea about your pH?

[mangoba]

Usually the rain water collector surface (roof) builds up some dissolvable minerals.

Thank you, it also gets stored for months in a concrete well so that must contribute also.

[achetadomestica]

My soil is white sand.
Mangos need very little fertilizer. They do love water
You may be making this too complicated?

That's exactly what I'm thinking, how much roughly do you give them and do you have an idea about your pH?

My ph is 6.3
My scoop is 4 oz. I give the trees 2-3 scoops every month
I start March 1st and end after September or October 1st
I bought one 50lb bag of fertilizer last March and fertilize
around 15- 20 trees including some avocados each month.
The bag is almost gone and it's close to the end of the season.