Sunday 9 March 2008

top soil question

Has anyone else in the valley noticed how quickly the topsoil dries out. Since the good rain we have had I decided to plant some trees. I had some seeds that I'd potted up and they were growing strong, so it was time for them to go out into the big world. The hole were dug, fertiliser was ready so in they went.

I noticed when I was digging the holes that the first 50 to 70mm was dry. Under that the soil was moist, and the clay layer was wet. I thought that all the extra water that these trees would need was a good wetting-in on planting.

It was surprising that on inspection two days later the trees were showing all the symptoms of lack of water.

The topsoil was bone dry and the more disturbed the soil the deeper the dryness. Where I had dug the holes for the trees the dryness extended a good 100mm or more.

This has led me to thinking about what would cause this problem. Since most of the trees were well mulched when they were planted, direct sunlight should not have caused the drying soil.

We have not had extremely hot weather so that could not be the cause either.

This made me think about the drought we have just had. Could it be that over the combined dry years the humus in the soil has depleted to such an extent that it leaves the surface topsoil vulnerable to drying?

This is my current theory, but I am open to other suggestions.

If you have noticed the same thing in your garden in the Clarence Valley I would be very interested to hear of your experiences and what you think may be causing this. Or is it just my imagination?

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