Soil from dredged khlong

[kuma]

Good day

Hoping to tap the expertise here regarding soil. In my area, SE thailand, they are currently dredging a khlong. Its source is a nearby hill, at about 1000-1500m...a park so cant get in to check exactly. The warer runs from that source thru khlongs, a river, then an estuary, ending in the gulf. The dredge is happening high up near the source, so the water is 100% fresh, no saline. 

Would you think this soil is good for landfill/top soil? I have some land right at the dredge site and was thinkong of asking them to dum the soil on my property. Just not sure if that would be a good plan or if tgat khlong soil might have a poor composition as top soil for growing fruit n veg etc.

Thanks in advance for any comments. We have a regional soil test centre and i am taking some samples there but intrrested what the forum might have to say.

Cheers 

[PatchinExPat]

The only down side I see is if there was a lot of heavy metals 

or chemical residue in the canal.

I expect the soil is washed away top soil.

[steven100]

Unless you are really keen to have this Klong dredged soil I would be reluctant to do so. 

I would doubt it's use especially for top soil.

If saving money was the reason I would pay more to have proper land fill & topsoil.

Once the soil is dumped as fill it will begin to dry out and oxidize. 

Following on-land disposal, dredged sediment is initially subjected to drying and oxidation. Important factors influencing changes in the sediment are: the type and amount of clay minerals, caption exchange capacity (CEC), organic matter content, pH, redox potential and salinety.

Metals are released when their sulphides are moved into oxidizing environments where they are unstable: the oxidation resulting in acidification of soils or sediments.

 

 

 

Edited June 24, 2020 by steven100

[kuma]

7 hours ago, steven100 said:

Unless you are really keen to have this Klong dredged soil I would be reluctant to do so. 

I would doubt it's use especially for top soil.

If saving money was the reason I would pay more to have proper land fill & topsoil.

Once the soil is dumped as fill it will begin to dry out and oxidize. 

Following on-land disposal, dredged sediment is initially subjected to drying and oxidation. Important factors influencing changes in the sediment are: the type and amount of clay minerals, caption exchange capacity (CEC), organic matter content, pH, redox potential and salinety.

Metals are released when their sulphides are moved into oxidizing environments where they are unstable: the oxidation resulting in acidification of soils or sediments.

 

 

 

Steven

Thanks for taking the time to reply, appreciate the info. I was thinking of taking advantage of the soil only because they are doing the work right in front of the land. I dont really need any but extra never hurts.

What you describe sounds like wgat happens when they drain those pits they use for fish n seafood farming...but i think that soil is even more ladened with vitamin residue, chemicals and fish waste.

They have not started putting soil on the land so i have some time. I think i will get some tested at the provincial lab, they do it for free and give a full report.

Cheers for the input

[steven100]

4 hours ago, kuma said:

Steven

Thanks for taking the time to reply, appreciate the info. I was thinking of taking advantage of the soil only because they are doing the work right in front of the land. I dont really need any but extra never hurts.

What you describe sounds like wgat happens when they drain those pits they use for fish n seafood farming...but i think that soil is even more ladened with vitamin residue, chemicals and fish waste.

They have not started putting soil on the land so i have some time. I think i will get some tested at the provincial lab, they do it for free and give a full report.

Cheers for the input

that's a good idea, i was going to suggest you discuss with a soil expert but i wasn't real sure if there were any around, but the testing is even better and they may also be able to tell you their opinion.

I mean it may be ok to use as fill, I just wanted to mention what happens after the soil comes out.

thanks & good luck with it. let me know later.

[kuma]

On 6/25/2020 at 6:17 AM, steven100 said:

that's a good idea, i was going to suggest you discuss with a soil expert but i wasn't real sure if there were any around, but the testing is even better and they may also be able to tell you their opinion.

I mean it may be ok to use as fill, I just wanted to mention what happens after the soil comes out.

thanks & good luck with it. let me know later.

Good day

So after a long wait the results of the soil analysis is complete. Given the time that has passed, the dredged soil is no longer available for topsoil but here are the results, both for the land I bought, and the dredged canal soil. 

Rather than make a table, I will list each measurement and the results, first number would be the khlong soil, second the land.

 

Acid Alkali: 4.70 / 5.16

Electrical Conductivity (google translate) ms/cm: 0.04 / 0.03

Organic Matter %: 0.26 / 0.22

Phosphorus mg/kg: 12.31 / 2.40

Potassium mg/kg: 19.18 / 161.62

Calcium mg/kg: 153.91 / 223.73

Magnesium mg/kg: 49.33 / 46.36

 

Thats the full spectrum available. There were other categories but they were not completed. 

In any event we have pushed on and have planted a fair number of plants to kick off; mango x 3, durian x2, lime, banana x2, Coconut, Dragon Fruit and more. All actually seem to be catching on nicely to date, even through the pounding rain we had this month.

Any comments on the above is appreciated.

Cheers