Rice Straw

[Deke]

We are studying the construction of a biomass-fired power plant in northern Thailand and have identified rice straw as a likely fuel source. Because my background is mostly in the power generation side of things, I was hoping that some of you rice farming experts could help me with a few agricultural-related questions:

1. Where rice is harvested manually, what proportion of the plant is collected and what proportion is typically left in the field?

2. Same as above for mechanical harvesting methods. When a mechanical harvester is used, is any of the straw normally collected?

3. What normally happens to the uncollected straw? Is it burned in the field, plowed into the soil or some combination of the two?

4. Is there any reason that, given some incentive, the straw which is currently left in the fields could not be collected?

5. What are traditional or possible competing uses for straw that is collected?

6. Can anybody make a wild guess as to what proportion of available straw is actually collected and utilized?

7. Does anybody have any ideas of other issues that should be considered with regard to collecting and using rice straw?

Thanks in advance for any information or suggestions that anybody might be able to provide.

[Khonwan]

Hi Deke

I can only help you with part of your query. A percentage (high, I would think) of manually harvested rice is either baled (with a stationary baler, which I used to use and still own for my former cattle) or transported loose for cattle dry-season feed. Same with the mechanically harvested rice – a tractor-pulled baler collects and bales much of this to be sold mostly to cattlemen.

Rgds

Khonwan

[Deke]

Hi Deke

I can only help you with part of your query. A percentage (high, I would think) of manually harvested rice is either baled (with a stationary baler, which I used to use and still own for my former cattle) or transported loose for cattle dry-season feed. Same with the mechanically harvested rice – a tractor-pulled baler collects and bales much of this to be sold mostly to cattlemen.

Rgds

Khonwan

Thanks Khonwan. Any idea of the price that the baled straw is sold for?

[Khonwan]

Sold for around 20 baht / bale two or three years ago; haven't priced it lately but would imagine the price has risen to perhaps 25 baht.

Rgds

Khonwan

[Deke]

Sold for around 20 baht / bale two or three years ago; haven't priced it lately but would imagine the price has risen to perhaps 25 baht.

Thanks again Khonwan.

[slapout]

Those areas that plant garlic will use the rice straw as a mulch on the garlic plants. Said farmers will not sell for this reason.

[jandtaa]

up here in Chiang Rai when manually cut I would guesstimate that 40 % of the tiller length remains in the ground (how low do you want us to bend over ? ) some people will then use a mechanical thresher the resulting straw is then gathered by the local lads and sold to cattle farmers or mushroom growers or kept for own use (cattle feed or mulch for vegetables sometimes composting ) others that still thresh manually sell strictly to mushroom growers to cultivate " hed fang kaow" straw mushrooms. As soon as a plot of paddy is harvested a local wiil turn out his cattle onto your land to eat the stubble and any late season weeds. many people will burn off the remainder before replanting corn or soy beans but there is very little left by the new planting season.

[Deke]

up here in Chiang Rai when manually cut I would guesstimate that 40 % of the tiller length remains in the ground (how low do you want us to bend over ? ) some people will then use a mechanical thresher the resulting straw is then gathered by the local lads and sold to cattle farmers or mushroom growers or kept for own use (cattle feed or mulch for vegetables sometimes composting ) others that still thresh manually sell strictly to mushroom growers to cultivate " hed fang kaow" straw mushrooms. As soon as a plot of paddy is harvested a local wiil turn out his cattle onto your land to eat the stubble and any late season weeds. many people will burn off the remainder before replanting corn or soy beans but there is very little left by the new planting season.

Thanks. I'll be up that way next week to have a look around but this kind of information is very helpful.

[pnustedt]

I farm and contract harvest rice, and bale it as required, in the Sisaket area. I'll try to answer your questions:

We are studying the construction of a biomass-fired power plant in northern Thailand and have identified rice straw as a likely fuel source. Because my background is mostly in the power generation side of things, I was hoping that some of you rice farming experts could help me with a few agricultural-related questions:

1. Where rice is harvested manually, what proportion of the plant is collected and what proportion is typically left in the field? I think the proportion will be extremely low. The process does not lend itself to a pick-up baler and the farmers probably couldn't afford baling anyway.

2. Same as above for mechanical harvesting methods. When a mechanical harvester is used, is any of the straw normally collected? We do baling for mechanical harvesting. The takeup is not large, we do a few thousand bales a year on paddies - we harvest a few thousand rai/year.

3. What normally happens to the uncollected straw? Is it burned in the field, plowed into the soil or some combination of the two? Uncollected straw is normally ploughed in my area (Sisaket), there is very little burning here. Cows do graze the fields for a few months tho.

4. Is there any reason that, given some incentive, the straw which is currently left in the fields could not be collected? If there was a way of making money without too much effort I am sure that many Thai farmers would jump at the chance.

5. What are traditional or possible competing uses for straw that is collected? Cattle feed, especially during the season when rice is growing in the paddies and mulching various crops, onions, chillies, etc.

6. Can anybody make a wild guess as to what proportion of available straw is actually collected and utilized? This is a wild guess, but I would reckon less than 10%

7. Does anybody have any ideas of other issues that should be considered with regard to collecting and using rice straw?Logistics. You would need someone to bale it, store it, transport, ensure the farmers are paid. It is quite bulky stuff.

Thanks in advance for any information or suggestions that anybody might be able to provide.

[Foreverford]

I farm and contract harvest rice, and bale it as required, in the Sisaket area. I'll try to answer your questions:

We are studying the construction of a biomass-fired power plant in northern Thailand and have identified rice straw as a likely fuel source. Because my background is mostly in the power generation side of things, I was hoping that some of you rice farming experts could help me with a few agricultural-related questions:

1. Where rice is harvested manually, what proportion of the plant is collected and what proportion is typically left in the field? I think the proportion will be extremely low. The process does not lend itself to a pick-up baler and the farmers probably couldn't afford baling anyway.

2. Same as above for mechanical harvesting methods. When a mechanical harvester is used, is any of the straw normally collected? We do baling for mechanical harvesting. The takeup is not large, we do a few thousand bales a year on paddies - we harvest a few thousand rai/year.

3. What normally happens to the uncollected straw? Is it burned in the field, plowed into the soil or some combination of the two? Uncollected straw is normally ploughed in my area (Sisaket), there is very little burning here. Cows do graze the fields for a few months tho.

4. Is there any reason that, given some incentive, the straw which is currently left in the fields could not be collected? If there was a way of making money without too much effort I am sure that many Thai farmers would jump at the chance.

5. What are traditional or possible competing uses for straw that is collected? Cattle feed, especially during the season when rice is growing in the paddies and mulching various crops, onions, chillies, etc.

6. Can anybody make a wild guess as to what proportion of available straw is actually collected and utilized? This is a wild guess, but I would reckon less than 10%

7. Does anybody have any ideas of other issues that should be considered with regard to collecting and using rice straw?Logistics. You would need someone to bale it, store it, transport, ensure the farmers are paid. It is quite bulky stuff.

Thanks in advance for any information or suggestions that anybody might be able to provide.

Till it back into the soil to try to increase the tilth and sttructure of your soil (the world's body and blood). Put anything else you can on your soil (NO not salty chem fertilizers) that will add to the sustainability of your precious land before doing so or just keep depleting it by trying to take every possible thing from the soil without giving it anything back. Sorry for the sarcasm but when will we learn. Hopefully in a few years i'll have some very viable solutions and help but I'm just a dumb (and getting older and dumber farmer)

[IraqRon]

Sold for around 20 baht / bale two or three years ago; haven't priced it lately but would imagine the price has risen to perhaps 25 baht.

Rgds

Khonwan

Khonwan, could you give me an idea of the size of your bales, are they consistent from bale to bale, what is the avg lenght of the rice stems that are baled, what is the avg weigth of the bale? Dryness?

Can you customize your bale size and/or density (weight).

I am interested in using straw bales in a project and they must be around 7-9 lbs per sq ft, dry, and mostly consistent in size.

The original poster suggested using rices straw in a biomass project, and I think that means using the heat generated in decomposition to produce electricity or the gases to produce elect. I have found rice straw to break down very slowly, even when kept wet. Don't know if it will lend itself to his project but if so then I wish him well. It would be a better use than burning it in the fields as much is done in CR area, and many others.

[Deke]

The original poster suggested using rices straw in a biomass project, and I think that means using the heat generated in decomposition to produce electricity or the gases to produce elect. I have found rice straw to break down very slowly, even when kept wet. Don't know if it will lend itself to his project but if so then I wish him well. It would be a better use than burning it in the fields as much is done in CR area, and many others.

Actually, our plan is to burn it. Either directly (with appropriate emissions controls) or by gasifying it first (thermally, not by decomposition). Either way, we will in theory end up with a carbon neutral process by burning it to replace fossil fuels for power generation.

I visited the project area (northern Chiang Mai province) last week. There is certainly no baling going on around there. The community leaders were quite enthusiastic about finding a market for what is, to them, a waste product.

[Khonwan]

Hi IraqRon

I’ll check the height and width of the bales tomorrow but from memory (haven’t used it in some 4 years or so) they are both around 45cm. The length of the bale can be controlled with practise since the baling is a manual operation – they are normally baled at twice the width, which is more conducive for stacking. Density can also be controlled, though I’ve no idea how to measure it. From memory, they weighed 15kg. Stem lengths? Never paid attention to this. Dry matter percentage? Never measured, but very dry.

Do you intend using them for construction?

Rgds

Khonwan

[Lickey]

Using rice straw or any other kind of mulch is a really bad idea in my opinion if you irrigate as well, its a haven for ants and snails, therefore mealy bugs and ahpids, which ants use to find them food,

AS Foreverford said, plough it in, re-stucture your soil, anything can be composted, i now have approx 3 tonnes and the cost? just my labour, it will be used in the salad beds when they start growing weeds again, as USUAL the thai labour sprayed weedkiller at to strong a mix in September and nothing grows,,,

[Khonwan]

Hi IraqRon

I’ll check the height and width of the bales tomorrow but from memory (haven’t used it in some 4 years or so) they are both around 45cm. The length of the bale can be controlled with practise since the baling is a manual operation – they are normally baled at twice the width, which is more conducive for stacking. Density can also be controlled, though I’ve no idea how to measure it. From memory, they weighed 15kg. Stem lengths? Never paid attention to this. Dry matter percentage? Never measured, but very dry.

Do you intend using them for construction?

Rgds

Khonwan

Just checked my machine: 40cm x 40cm x 80cm; c.15kg.

[IraqRon]

Hi IraqRon

I'll check the height and width of the bales tomorrow but from memory (haven't used it in some 4 years or so) they are both around 45cm. The length of the bale can be controlled with practise since the baling is a manual operation – they are normally baled at twice the width, which is more conducive for stacking. Density can also be controlled, though I've no idea how to measure it. From memory, they weighed 15kg. Stem lengths? Never paid attention to this. Dry matter percentage? Never measured, but very dry.

Do you intend using them for construction?

Rgds

Khonwan

I did a guesstimate based on a 40cmx40cmx80cm bale, at 15 kg. I had to convert it to inches, and lbs and came up with that being about 4.5 cubic feet. That would be about 7 lbs per cu ft which is the minimum dry density I would need for load bearing. Ideally the bail would be say 16" X 16" X 33 " but in Thai could get by with smaller than 16" thick, but the length extra would be good. So anyway, balled slightly tighter (maybe) your size would do.

I have seen bailed rice straw up around my place outside CR and plan to check it out in Jan. see what the farmer has.

What kind of bailer do you use?? Power? can bail when cutting the standing stems? From my experience, most is cut and stacked in piles and then burned. Really doesn't make good compost and not so good for animal feed either as the nutrient content is almost zero. But rice straw is the best for baling.

Yes, I am planning a construction project with it. Lets keep in touch on this.

Ron

[Khonwan]

Hi IraqRon

I'll check the height and width of the bales tomorrow but from memory (haven't used it in some 4 years or so) they are both around 45cm. The length of the bale can be controlled with practise since the baling is a manual operation – they are normally baled at twice the width, which is more conducive for stacking. Density can also be controlled, though I've no idea how to measure it. From memory, they weighed 15kg. Stem lengths? Never paid attention to this. Dry matter percentage? Never measured, but very dry.

Do you intend using them for construction?

Rgds

Khonwan

I did a guesstimate based on a 40cmx40cmx80cm bale, at 15 kg. I had to convert it to inches, and lbs and came up with that being about 4.5 cubic feet. That would be about 7 lbs per cu ft which is the minimum dry density I would need for load bearing. Ideally the bail would be say 16" X 16" X 33 " but in Thai could get by with smaller than 16" thick, but the length extra would be good. So anyway, balled slightly tighter (maybe) your size would do.

I have seen bailed rice straw up around my place outside CR and plan to check it out in Jan. see what the farmer has.

What kind of bailer do you use?? Power? can bail when cutting the standing stems? From my experience, most is cut and stacked in piles and then burned. Really doesn't make good compost and not so good for animal feed either as the nutrient content is almost zero. But rice straw is the best for baling.

Yes, I am planning a construction project with it. Lets keep in touch on this.

Ron

Hi Ron

Checking my tape measure, I see that 16" equals 40.6cm - I expect my bales are therefore 16" as I wasn't being too exact when I measured it. 33" length can be produced since the length is controlled by the operator.

My baler is a stationary type suitable for manually cut rice. It was specially built to my order several years ago to be belt-driven by a Kuboto engine or direct via tractor PTO (power take off). I used my Ford 6600 to power it. The baler is currently in storage as I no longer farm cattle.

Actually, rice straw isn't that bad a feed for cattle in the dry season IF a solution of urea, molasses and water is sprayed over it before feeding to the cattle. The urea effectively makes the treated straw provide around 8% protein - fairly similar to maize. I fed it to my 160 head of cattle with very good results throughout the dry season.

Rgds

Khonwan