How does excess irrigation causes salinity in the soil?
How does excess irrigation causes salinity in the soil?
If salts accumulate in soil due to irrigation, then it’s because the salts are IN THE IRRIGATION water.
Most of the irrigation water evaporates, or is taken up by the crop, with some penetrating deep into the soil in some cases. When the water evaporates, the salts are left behind.
And when the crop takes up water, it leaves the salt behind as well.
So if you irrigate with water with dissolved salts in it, then the salts accumulate in the soil. It’s possible that if you irrigate long enough, you will harm the soil.
It’s as simple as that.
And MOST irrigation water contains at least a trace of various salts. Some is salty enough it is barely usable short term, and such water ruins the soil over the long term.
Now if you use ENOUGH irrigation water, so that a substantial portion of it runs off, or penetrates down to the water table, then the water itself tends to wash away some of the PREXISTING salts in the soil, so that a balance is struck. If you irrigate with PLENTY of water with very low salt levels, the water itself will flush out it’s own salts, leaving the soil in about the same condition in respect to salt levels year after year, decade after decade.
The problem is that irrigation water is expensive, and in short supply, and farmers are unable or unwilling to buy more than necessary to make this years crop.
If salts accumulate in soil due to irrigation, then it’s because the salts are IN THE IRRIGATION water.
Most of the irrigation water evaporates, or is taken up by the crop, with some penetrating deep into the soil in some cases. When the water evaporates, the salts are left behind.
And when the crop takes up water, it leaves the salt behind as well.
So if you irrigate with water with dissolved salts in it, then the salts accumulate in the soil. It’s possible that if you irrigate long enough, you will harm the soil.
It’s as simple as that.
And MOST irrigation water contains at least a trace of various salts. Some is salty enough it is barely usable short term, and such water ruins the soil over the long term.
Now if you use ENOUGH irrigation water, so that a substantial portion of it runs off, or penetrates down to the water table, then the water itself tends to wash away some of the PREXISTING salts in the soil, so that a balance is struck. If you irrigate with PLENTY of water with very low salt levels, the water itself will flush out it’s own salts, leaving the soil in about the same condition in respect to salt levels year after year, decade after decade.
The problem is that irrigation water is expensive, and in short supply, and farmers are unable or unwilling to buy more than necessary to make this years crop.
