Everytime I plant a tree and its principal root reaches 5 meters deep, the tree dies? What could be the cause?

Question

I've been planting an Indian tree on a certain area in our front yard. But everytime the height of the tree reaches 5 meters and its principal root reaches I guess 4 or 5 meters, too, the tree would then start to turn into brown in color and totally dies. I wonder what is wrong or what is beneath that no plant could grow in that certain area? According to a contributor, it might be because of high watertable and salinity. If that would be the case, I wonder why the other two trees of same length 1 meter away from it did not die. Please help. I can't find sites that could give me exact answers. Thank you.

Answer 1

It could be a lot of things. But if other trees nearby aren't affected it has to be something very local, relatively small.
Could be a mineral deposit just in that area 4 or 5 meters down - any number of salt compounds, perhaps minerals with arsenic or other toxic elements in them (that would only affect that one tree's roots because the roots would absorb water that leeched the minerals out in just that one area).

I think you have to dig down 4 or 5 meters and see what's down there.

Answer 2

Pure guesswork here;
It is unlikely that a natural soil mineral or groundwater condition would be localized within 2 Meters.
Is it possible the taproot is hitting a sewer line or septic tank top?
Buried and abandoned oil tank?

1 Meter apart is pretty dense planting for trees.
Is there competition for light?

Are the other two of the same species?
Some plants do manage to eliminated crowding
chemically, (both 'intra` and 'extra` species).
( Some research might be in order.)

Answer 3

Are u introducing the plant there? Is it natural? Well, two things pop into mind. Pollution. Everytime it rains the watertable rises, connecting a lot of things. Any poisons people have been using near bye? Any invasion of bugs?

Answer 4

The soil is probably acidic or possibly poluted at that depth. Try doing a PH test on the soil at that depth.