Mangos and nitrogen

[Zarafet]

It's my understanding that mangos are sensitive to nitrogen. Does this apply to all nitrogen sources or just the synthetic sources? Would natural nitrogen from, say, composted chicken manure be ok or does sensitivity apply to ALL nitrogen?

[Mark in Texas]

It's my understanding that mangos are sensitive to nitrogen. Does this apply to all nitrogen sources or just the synthetic sources? Would natural nitrogen from, say, composted chicken manure be ok or does sensitivity apply to ALL nitrogen?

Have it lab tested or you're only guessing.

Been giving my young mango trees a 18-4-9 slow release.  This to induce a good root system and canopy.  (No, high P foods "for good roots" is label marketing bullshit).  As they enter their fruiting stage now I'm backing off the N and increasing K.  Also top dressed with gypsum.

[greenman62]

Try using nitrogen fixing plants.

i have several beans, senna, autumn olive next to my trees
even in containers.
Just need to keep the foliage from shadowing the fruit trees
but  most N fixers take pruning/coppicing well.

[Zarafet]

How do nitrogen fixers actually work? Do you chop and drop or do they pull nitrogen into the soil?

Try using nitrogen fixing plants.

i have several beans, senna, autumn olive next to my trees
even in containers.
Just need to keep the foliage from shadowing the fruit trees
but  most N fixers take pruning/coppicing well.

[Seanny]

Nitrogen fixer absorbs nutrients from dirt to grow. There is no free lunch.

[Clay]

As I recall, nitrogen fixers such as legumes, work with microbes to take nitrogen from the air (N2) and produce water soluble nitrogen compounds such as ammonia. Using the plants as a green manure releases that nitrogen to the soil as the plant breaks down.

[DesertDreamer]

You are both right.  Legumes fix nitrogen from the air via symbiotic N fixing bacteria.  However, they fix less than 100 percent of their own needs, and will consume other nutrients.  Some other plants nearby will benefit from nitrogen that 'bleeds' away from the rhizosphere, but the main benefit is seen when legumes are cut and used as mulch and they return a portion to the soil.  Some plants like a slow drip of nitrogen that leaks from legumes, but I have found only marginal benefit from this.  Not NO benefit, but only small benefit. 

[greenman62]

There are several types of N microbes associated with nitrogen fixation.
and several types of N fixing plants.

Legumes have nodules on  the roots
these nodules die often and release nitrogen to the surrounding soil.

There are other "free living" type rhizobia.

Yeah, the leaves and stems are great mulch, but the real benefit is from the bacteria.
it is used on a regular basis in agriculture, (like soy) planted before corn and such...

--------

 "Nodules on annuals are short-lived and will be replaced constantly during the growing season"
http://www.csun.edu/~hcbio027/biotechnology/lec10/lindemann.html

All the nitrogen-fixing organisms are prokaryotes (bacteria). Some of them live independently of other organisms - the so-called free-living nitrogen-fixing bacteria. Others live in intimate symbiotic associations with plants or with other organisms (e.g. protozoa).

In addition to these intimate and specialised symbiotic associations, there are several free-living nitrogen-fixing bacteria that grow in close association with plants. For example, Azospirillum species have been shown to fix nitrogen when growing in the root zone (rhizosphere) or tropical grasses, and even of maize plants in field conditions. Similarly, Azotobacter species can fix nitrogen in the rhizosphere of several plants. In both cases the bacteria grow at the expense of sugars and other nutrients that leak from the roots.

http://archive.bio.ed.ac.uk/jdeacon/microbes/nitrogen.htm

 nitrogen fixation by legumes can be in the range of 25–75 lb of nitrogen per acre per year in a natural ecosystem, and several hundred pounds in a cropping system

Other grain legumes, such as peanuts, cowpeas, soybeans, and fava beans, are good nitrogen fixers and will fix all of their nitrogen needs other than that absorbed from the soil. These legumes may fix up to 250 lb of nitrogen per acre and are not usually fertilized (Walley et al., 1996; Cash et al., 1981). In fact, they usually don’t respond to nitrogen fertilizer as long as they are capable of fixing nitrogen. Nitrogen
Perennial and forage legumes, such as alfalfa, sweet clover, true clovers, and vetches, may fix 250–500 lb of nitrogen per acre

 // Almost all of the fixed nitrogen goes directly into the plant. However, some nitrogen can be “leaked” or “transferred” into the soil (30–50 lb N/acre) for neighboring non-legume plants (Walley et al., 1996). //

http://aces.nmsu.edu/pubs/_a/A129/

[greenman62]

Not all N fixing plants are created equal

great site that shows which N fixers are best.
alfalfa, Autumn olive and white clover are excellent.
http://www.perennialsolutions.org/all-nitrogen-fixers-are-not-created-equal

[Mark in Texas]

As I recall, nitrogen fixers such as legumes, work with microbes to take nitrogen from the air (N2) and produce water soluble nitrogen compounds such as ammonia. Using the plants as a green manure releases that nitrogen to the soil as the plant breaks down.

They do fix N from the air in root nodes. I spent 3 consecutive years and thousands of dollar on contract labor and (innoculated) seeds and planted legumes and elbon rye on my farm, 14 acres worth.  Make sure your selections will work for your area and soil type.

[fyliu]

There are other "free living" type rhizobia.

Interesting, so rhizobia can live free but can't fix nitrogen unless paired with a plant host.
https://en.wikipedia.org/wiki/Rhizobia

I looked it up thinking it's not a real word.