Caliche sandy soil , could it be hydrophobic one ?

In a certain spot in my farm , where grey water from the kitchen run , there was a soil like no other , it creates top soil fast , it grows plant like leblab and lofa like no other.

I know that for 4 years or so , but couldn't really figure out the reason , I thought it might be the food left over that might be doing the trick .

later on, it came to my mind that the liquid soap wash might have something to do with it , what we learnt from childhood that soap water kills your plants

 I have to mention that my soil is sandy one , so I picked another spot in my farm and added some soap liquid with a lot of water . what appears to me that water don't leach down so fast as it used to do .

what in my mind now and I might be wrong is : I think that my soil is hydrophobic one it leaches water down so fast through cracks  ,and so little water gets to the plant roots , so dish washing liquid acted as wetting agent that did a better job with my soil .

my questions are ,
am I right ?
what am I  missing ?
how can I make a natural wetting agent ?
,
my soil is in end of the desert , it's almost caliche ,we get almost no rain all the time , we have to till big and add lots of manure every time we grow new crop, most of the near by farm use lot of chimical fertilizers  ,herbcide , pest and fung cide  ,no till method was not good idea at all . summer is really hot and long

I tried lots of natural things with little help




I might not be around in the next 2 weeks i

Hello

I have no practical knowledge of Egyptian soils. So take this with a pinch of salt.

So i might be wrong but what will be happening is that your grey water sustains a locally adapted group of bacteria and fungi in that spot. That may improver your soil and explain part of what is happening.
A trained observer may spot this kind of ecological rebound f.e. in places were greywater is released in ditches or such. A ditch that has been receiving some slightly polluted grey water for a long time recovers often faster than a ditch in which no so greywater is released. The standard explanation for this is that the local bacteria and fungi in the soil and water bottem are 'selected/trained' to break down the pollutants.
Broken down organic 'pollutants' in the greawater (cooking oil residu, soaplike substances, food residu, excrement, etc..... become part of the organic matter in the soil. Nutrients and water are better retained by organic matter.

As to the increased water retention. If you bring something into the soil that helps clogg up the drainage of your soil, you will gett more water into the top soil. It is one of the changes to soil properties you can observe near oil spills in soil.
To be clear DO NOT spill oil. Bad, bad idea soil and groundwater become toxic.
Oil, soap, dissolved fat, detergent, etc... may form coatings around sand grains and in cracks of the caliche reducing permeability and increasing waterretention.

You may have similare effects by using water with suspend clayparticles.


In the long term you may have a saline build up in that soil.

Either way, if you have an agricultural college nearby you may interest people there to check what is happening in your soil. Also check Bryant Redhawk on this site.