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Lawn fertilizer versus aquatic

tiger15

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14 Mar 2018
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I am wondering why lawn fertilizer has so much higher N to K ratio than aquatic fertilizer. Typical lawn fertilizer in US for NPK is 30,0,5 versus EI aquatic 20,1,20. If plants can grow only as fast as the limiting nutrient, why is it beneficial to have extraordinary high ratio of N to K for lawn.. is there fundamental difference between terrestrial and aquatic plants?
 
Yes and no, it all depends on the plant sp. some are absolute fert hogs especialy the faster growing plants. Also bulb plants are extreme fert hoges,
Take for example the Potato, this plants depeletes the soil that heavily a farmer never grows it constantly on the same field, needs to remineralize a previous Potato field with green manure and grow something else less demanding on it again for a seaon or 2 to give the soil a chance to recover.

Next to this terrestrial plants have non limited access to CO² (400ppm) there for can grow much faster, thus utilize much more fertilizer from the soil.

Terrestrial plants that are forced to grow aqautic only have a fraction of this CO² available, depending if you add it or not between 1ppm and 30ppm.
This significantly slows down its grow process. If you would give the plant an equal amount of ferts it can not utlize it and you create an eutrophic aquatic invironmnet that doesn't benefit the development of a healthy aqautic eco system. Eutrophic conditions deplete oxygen, the nitrifying bacteria etc. needed to fight eutrophy have a high oxigen demand.

Other difference is, because of the much higher metabolisme in plants from a non aqautic condition, there also is no oxygen limitation for the bacteria in the soil. There for will be pressent in higher numbers able to work harder. Now fertilizer for terrestrial plants contains Urea and Ammonia based nitrogen source. The plant itself and the bacteria in the soil will have no problem converting this to usefull building blocks.

In an aqauric invironment Urea and Ammonia is highly toxic to aqautic lifeforms. Since it needs a high oxygen demand to readily convert this to N and since oxygen is a limited source in an aqautic invironment this stuff will accumulate to toxic levels and killl all your fish.

Thus the fundamental difference in the recomended fertilizer is more aimed towards the safety of the life stock living next to plants in the water.

This is about it in a nutshell.. :)
 
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H all,
I am wondering why lawn fertilizer has so much higher N to K ratio than aquatic fertilizer. Typical lawn fertilizer in US for NPK is 30,0,5 versus EI aquatic 20,1,20.
The high nitrogen feed gives you a rapid greening and growth response in the spring. If it is "weed and feed" it may also contain ferric ammonium sulphate as a combined fertiliser/moss killer.

Usually there is <"another formulation"> (that you put on in the autumn) which is low in nitrogen (N), but contains a higher ratio of P and K. Lawn grass is usually a "sports" Rye grass (Lolium perenne) now specifically chosen for its rapid growth response to nitrogen and wear tolerance

The "ideal" lawn has thick even grass growth, which you then mow frequently, but not too short, so that you get the "thick green carpet with stripes" look.

I can see the point of this if your lawn is a sports field or a golf course, if it is your home lawn I can't.

My ideal lawn is full of Daisies (Bellis perennis) (favoured by trampling), Clover (Trifolium repens) and rosette herbs like Cat's-ear (Hypochaeris radicata), if you can deplete nutrients far enough you can end up a with a flowery lawn that only needs cutting once every six weeks or so.

It is a result, every-one else is mowing their lawn and you are sitting in the garden having a beer, watching the bees.

cheers Darrel
 
My ideal lawn is full of Daisies (Bellis perennis) (favoured by trampling), Clover (Trifolium repens) and rosette herbs like Cat's-ear (Hypochaeris radicata), if you can deplete nutrients far enough you can end up a with a flowery lawn that only needs cutting once every six weeks or so.

It is a result, every-one else is mowing their lawn and you are sitting in the garden having a
beer, watching the bees.

Got to agree. I’d love a garden meadow, but my dogs prefer a garden that looks like the moon’s surface
 
but my dogs prefer a garden that looks like the moon’s surface

Ever had chicken?... I did, 13 tiny Chabo's a tad bigger than a dove but they make a 25m² lawn look like a WW1 batlle field in 1 summer with no grass left. Incredible little Japanese holigans.. :rolleyes:
 
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