Mr Farmer:
Nutrient competition in soil is related to the chemistry of soil. It may be a little technical, but what you'd need to know is that everything has a balancing point; too much of one thing can be just as bad as having too little.
The explanation of nutrient competition is as follows. It might sound sexist and crude, but please bear with me:
Think of nutrients as women on a shopping spree during the Big Sale. There are young teenage girls, there are 20-something girls, there are the more median aged women, and there are the more mature women.
Now think of clothing outlets as being plants, who depend on the "nutrients" paying a "visit" to their outlets in order to survive.
Each outlet would have particular types of items on sale prefered by those within certain age groups, and therefore "need" the specific age groups of women to come visit their store. Eg. teenage girls might go for clothing items worn by the Hunter Game's leading lady; 20-something girls would probably go for Korean girl-group fashoin, etc. etc.
So these outlets will have promotions from time to time to "attract" particular age groups of women to "visit". Often, these promotions are very targeted, whereby the age groups will hardly overlap. But once in a while, the outlet smight put on promotion something that is desired by multiple age groups (eg. LV bags are quite popular, I'm told). What happens, is a mad rush, which clogs up the outlet, resulting in delayed sales. In the case of actual outlets, well, they always get paid in the end; but for plants, this competition can starve the plants quite badly, damaging it significantly.
The second scenario is something like the above, except that in this case, there are less women during the Big Sale, and they are accompanied by non-targeted groups of people. We shall call them "non-targeted nutrients". Visualise them as the brothers, boyfriend, husbands, fathers, etc. etc. of these women. And all these fellas are super kiam siap dudes. And instead of being accompanied by one dude, each woman is accompanied by 2-3 or more (i.e. there are more dudes in the shopping mall than gals; not gonna happen, but hey, think creatively).
Normally, the "non-targeted nutrients" are quite liberal when going to the shopping malls with their women. But during Big Sale time, especially when there are less "nutrients" a.k.a. women for the outlets to woo and entice, these kiam siap brothers, boyfriends, husbands, fathers etc etc will hold on to their women tightly. Because they know, with so few other women about, the chances of "overspending" at those enticing outlets is very very high. In other words, if the women want to enter an outlet, the dudes will pull them away, thus preventing them from "visiting" and "spending" in the outlet. In plants, this literally worsens the state of starvation faced by the plant, accelerating whatever nutritional disease that is already present.
Now, with the right balance of all the above, things become very peaceful. No mad rushes, no controlling boyfriends/husbands/fathers etc. The outlets get their fair share of spenders, and there is no overspending.
Get the analogy?
In the case of what's probably happening to your plants, substitute scenario 1's "women" with potassium and magnesium. But consider magnesium as the more mature women who aren't nimble and quick-moving as the younger women (potassium), and are less in number in the shopping malls. The aggressiveness and sheer abundance of potassium being attracted to the plants outcompetes magnesium in being absorbed by the plant; this results in a "false" magnesium deficiency, which means that even though magnesium may be available is good quantity in the soil, the sheer amount of potassium greatly reduces the chances of any magnesium being absorbed. The more mature women (magnesium), although lower in number, generally have more cashflow than younger women (potassium), and so can impact the outlet's sales figure quite significantly; losing their business will put a dent in the bank account of the outlet in the long run.
Hope this paints a clearer picture.
And to any female readers we have, my apologies for the analogy; but you gals do make it simpler for us guys to visualise things.
This post has been edited by Michael J.: May 5 2012, 01:19 AM