When the pH of soil is low, aluminum becomes more soluable, but why is Al so bad for plants?

Question

does it keep nutrients out?

Answer 1

Being in the organic waste business, it is essential to avoid the buildup of persistent organic pollutants and heavy metals.

These two things are known to build up in biological tissue having effects such as lead poisoning and the like.

Aluminum will build up in plant tissue, and subsequently the tissue of any other animal that eats the toxic plant. However unlikely the case of being sick from it is, it does build up and over a life time it can cause irreparable harm. Only in the most extreme cases, such as around Aluminum smelters...

And for future reference do not buy aluminum cans, not for the risk of toxicitity but for the extra 3 litres of water it takes to make per can over a glass bottle of identical size.

Answer 2

it lowers the tree's productivity...meanign less photosynthesis. And ultimately makes the tree more suceptible to foreign invasion of illness, to the cold and to pests.

aluminium also leaches any good nutrients from the soil.

Answer 3

Keep in mind that aluminum is pretty abundant on our planet, more so in some areas than others. Aluminum, if I remember is mined in areas where other more soluble minerals have been lost/ leached out already and it is easier to get at, wet equatorial regions? Anyway, the pH of soils will determine what nutrients are available at what levels for a given plant. That is why pH is so important on the farm, garden, and the environment of field and forest. A plant that likes acid soil gets what they need at the right levels for a given pH and a higher one will not give the right levels and cause stress, disease, and death (poor yield as a minimum). Naturally occurring aluminum would not be an issue. The problem is that it is the pH that makes elements of the soil solution available to be used at a determined amount irregardless of the plant. If a low pH is required and attained from aluminum sulfate in the case of hydrangea, they form a nice blue flower color and a great healthy plant. Acid loving plants like Rhododendron also benefit. Aluminum is not required and is not an essential element for plants except that it influences and IS influenced by soil pH. At a pH of 7 aluminum is not available to a plant in the soil solution even when there is a lot of it. It will cause problems though when the pH is way too low and it will cause problems with plant growth, especially the root. The short answer is it is not aluminum that is the problem, it is the pH and that is too low.

Answer 4

A major consequence of soil acidification is the release of aluminum in its soluble forms from its insoluble forms, which, in turn, adversely affects the uptake of cations, causes organic acid secretion, and inhibits cell division and growth in the roots. Consequently, the respiratory metabolism is redirected to meet the needs of organic acid efflux from the roots.

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