Thread: foul smell from a paddy field

Hai,
My home is situated near a paddy field with meagre cultivation. For last six years
we used to suffer from a foul smell from the water in the field.
Some of the features of the area are giving below.The smell is so suffocating.
it starts from a piece of paddy field of a small area (0.20 acre) in front of my house. From here onwards upto 400 mteres along the flow of water thru a canal, often the smell is unbearable.
At the middle of the monsoon (Sepember every year)only the smell statrs. After a few weeks, the floor along the path of flow of water( Not anywhere else),that too for about a 50-70 meters , we see some white hair like growths (perhaps some algae). Later on we can see the floor along the flow gets entirly covered with this white growth, The grass, stones etc. along the path is also get covered with this white growth. Then towards December , when the water level in the field get lower and the flow of water become very low, the area covered by white growth starts turn green and the green colour spreads. At this time onwards the smell subsides. Its seems worthy to note that the smell do not subside compltely and also that the white growths still will be there but to a lesser extent.
I have also noticed that the colour of the water has no peculiar change, eventhogh the soil below is covered with whit growth.
I hope my dear friends could suggest some valuable inputs regardig the reason for this .

Is it used for agriculture, or just an unused field?

I wonder if it's a fungus type growth. My want to contact the city or county health department if the owner isn't near by.

The most common cause of smells like this are anaerobic bacteria. I assume that a lot of the water in and around the smelly areas are stagnant. The water is not moving, and this creates a layer of water near the bottom that has little or no oxygen dissolved in it. The anaerobic bacteria thrive under those conditions, and emit nasty gases.

If I am not mistken the white growth is Beggiatoa, which I believe uses reduced sulphur compounds.

You have anoxic conditions starting. Methane and reduced sulphur compounds are being produced. You probably smell the sulphur compounds.

A few possible reasons for this are:

Too much fertiliser
Too little water flow

--- which are leading to anoxic conditions. the green algaes consume the oxygen during the night, thus the anoxia, thus the growth of the bacteria that create the small.

Since production is meager can the field be drained? (anoxia is probably bad for the rice in any case.) Otherwise, perhaps suggest to the owner to change the fertilisation schedule.

My guess would be Methane, which rice fields are noted for. In fact along with all wetlands/rain forest, 75% of naturally produced methane come from these sources.

Sniff around a couple your electrical plug ins, around the house. You will get a mild but similar smell...

There won't be much you can do with the source, but you may be able to divert the overflow from the paddy field away from your house....

Originally Posted by jackson33

My guess would be Methane, which rice fields are noted for. In fact along with all wetlands/rain forest, 75% of naturally produced methane come from these sources.

Sniff around a couple your electrical plug ins, around the house. You will get a mild but similar smell...

There won't be much you can do with the source, but you may be able to divert the overflow from the paddy field away from your house....

Methane is odorless. The natural gas (mainly methane) in domestic supplies ids odorized with mercaptans to give it a smell. The smell from arcing electrical equipment is most likely ozone. The smell that the OP reported is probably H2S, (reduced sulfur as FR said).

Originally Posted by Bunbury

Originally Posted by jackson33

My guess would be Methane, which rice fields are noted for. In fact along with all wetlands/rain forest, 75% of naturally produced methane come from these sources.

Sniff around a couple your electrical plug ins, around the house. You will get a mild but similar smell...

There won't be much you can do with the source, but you may be able to divert the overflow from the paddy field away from your house....

Methane is odorless. The natural gas (mainly methane) in domestic supplies ids odorized with mercaptans to give it a smell. The smell from arcing electrical equipment is most likely ozone.

Mercaptans sound suspiciously like sulphur compounds, something I had not connected before. :-D

The smell that the OP reported is probably H2S, (reduced sulfur as FR said).

Except wot I spelled it proper.

Methane is odorless. The natural gas (mainly methane) in domestic supplies ids odorized with mercaptans to give it a smell. The smell from arcing electrical equipment is most likely ozone. The smell that the OP reported is probably H2S, (reduced sulfur as FR said).

Bunbury; Thanks for the correction...

Actually, methane doesn't smell either, but you probably thought it did because it is often found with hydrogen sulphide which is very stinky and smells just like rotten eggs.

http://www.thenakedscientists.com/HT...question/1295/

Originally Posted by free radical

Mercaptans sound suspiciously like sulphur compounds, something I had not connected before. :-D

Yes, there's a whole array of reduced sulfphur compounds that can occur in natural gas, and have to be taken out, and then the mercaptans are put back in in trace amounts. Carbon disulfphide and carbonyl sulfphide are sometimes in there. Do you like this spelling? I think everyone should be happy with this transatlantic compromize.

Hai friendz..

Thanks for ur enlightening comments.
I have to add to my OP, that one of my proffessor has collected the samples of theALGAE like growths and he had found that they are mostly OSCILLATORIA.
They have ensured us that the institute vl conduct a detailed study reg. why there is a localised concentration of such algae, as mentioned in OP.

Your comments are welcome
Srj[/quote]

Yuck. A stinky slimy bacteria that creeps like a slug. So is the "white growth" slime trails?

Thanks for the update. I'm curious to learn how you kill or replace this thing with better.

If I am not mistaken, Oscillatoria is a cyanobacterium (blue green alga) and non-motile, thus not responsible for the white growth. The white growth is Beggiatoa, more than likely. Beggiatoa indicates the presence of reduced sulphur.

The stink is neither from the Oscillatoria nor the Beggiatoa, rather from the reduced sulphur, which is being produced in the anoxic zones, perhaps in the sediment - I do not know offhand which organisms reduce the sulphur, though Archaea are often involved in this (as are some bacteria).

Chapter 2 (p35) may be useful:

http://books.google.com/books?hl=en&...age&q=&f=false

To the orignial poster:

Could there be sewage (human or animal) entering the field? Could the monsoons be bringing fertiliser-rich runoff from other regions? your situation sounds somewhat like fertiliser runoff (eutrophication). I believe the cycle is this:

~ Monsoon causes deeper water, which makes establishment of anoxic zone in sediment more likely (Monsoon may also bring wealth of nitrogen-rich compounds - fertiliser - to your field)

~ Anoxic zone allows sulphate reducers (as well as methanogens) to flourish, thus reduced sulphur is produced (the smell begins)

~ Beggiatoa (white hairlike organism) begins to grow (reduced sulphur is energy source for this organism)

~ As the water level drops, perhaps the anoxia is relieved (more oxygen diffuses to sediment) and this inhibits the sulphate reducers (as well as the methanogens) - No doubt the cyanobacteria are also remediating (improving) the area in some fashion, perhaps by competing for the remaining nitrogen sources?


The smell indicates anaerobic conditions (no oxygen) and this idea is consistent with your observation that the smell is worse when the water is deeper.

In any case, to prevent it, you need either to find a way to maintain oxygen in the sediment (this seems impractical) or to reduce other nutrients which are feeding into the base of the cycle, nitrogen being a key target. This is why I ask whether some form of fertiliser (or sewage or other) might be coming into the field.

Originally Posted by free radical

If I am not mistaken, Oscillatoria is ... non-motile

The clue is in the name. It oscillates.

The gliding motility is comparable to slugs. Slime is definitely a part of it, and there's presumably some kind of wave running along the surface.

But I think white hairs better explained by beggiatoa than slime trails.

Aha, cheers!