Cover Crops For Young Rubber Fields

[fremmel]

Has anyone tried using cover crops in newly planted rubber fields? Around here, in Udon, people seem to either intercrop with cassava or just plow the weeds in when they get too tall. That's all the rubber research station in Nong Khai knows about too.

We have a small 14 rai field that we planted this year. The soil is fine sand with a little clay and not much organic matter. The field also has a 1 to 2% slope. I'd like to try a cover crop to increase the soil fertility with organic matter and nitrogen fixing, crowd out the weed growth, and cut down on erosion.

I'm having trouble finding much information that's specific to rubber fields in Issan. Everything I've found on this forum and the Organic Farming forum is about using cover crops to prepare for field crops rather than intercropping with rubber. From googling it seems that cover crops are common in rubber plantations but everything is about southern Thailand, Malaysia, India, etc. Places that have climates and soils that are different from here. I have found a couple of references to academic studies in Isaan, here and a good one here , There seemed to be some good results but also possibly problems with resource competion between the cover crop and the rubber during the dry season and/or with acidification of the soil.

What would be nice to find is a perennial that's been used here that I can plant and maybe cut back now and again when it gets too tall. Even an annual would be better than just weeds. In the meantime, it's about time to plow the weeds in and what I thought to do after plowing was sow sunn hemp, let it grow for a couple of months, and then cut it back or plow it in. I've not found anyone that talks about sunn hemp with rubber but i'm guessing it would be beneficial.

So, what I'm hoping for is any actual, real world experience with this or some advice from people with more farming experience than I - which is just about everyone.

[Gonsalviz]

I grow corn in mine. Others have pineapple. The corn seems to be working well. I have many trees that have to be more than 3 meters. They were planted a year ago June.

[drtreelove]

http://www.thaivisa.com/forum/topic/382390-weed-control-any-ideas/page__p__3750249__hl__green+manure__fromsearch__1#entry3750249

There have been other discussions on cover cropping orchards, you just have to dig a little more. I don't remember one on rubber trees, but search 'weed control' (above), green manure, cover crops, sunhemp, sesbania, blackbeans, jack beans, mungbeans, etc.

Check with your local 'Land Development Dept' about their Dr Dirt program and free lugume seeds for green manuring. They will tell you what beans are available and help you calculate coverage rates, etc. You don't need a tabien baan from my experience, but take your Thai partner with ID, and location, acreage details, etc. They will also run a soil analysis if you take in soil samples. But I haven't personally used this program for a few years, so not sure of the current availability.

With a legume, the competition with the trees won't be primarily for nitrogen because the beans will fix their own; if you intercrop with a non-legume there will be more demand on nutrients and you may need to fertilize.

With legume or not you need to irrigate adequately in the dry season to supply both trees and cover crop.

[WatersEdge]

Hi Fremmel

You want someone to tell you a cover crop specific to Rubber?

Well, it is a pleasant surprise that someone actually wrote a paper on the specific topic.

Different crops for different seasons and local conditions.

I'd gather everything I could get my hands on for seed,

put it all in the ground and see what does best.

Then you can report back from a wealth of variety what the winning features were.

Roselle will start any time of the year,

flower in February and September

bear seed

There is a TV member looking for Kenaf Growers in Isaan

I think his screen name is EricThai?

Kenaf is a sister of Roselle => Hibiscus genus.

Beans aren't suitable for rainy season

because the leaves being high in protein will mold in high humidity.

Beans do fine as forage growth in rainy season,

cutting them at the first sign of leaf distress

but they will die before producing dry bean.

They are wonderful for mid August onward,

as they reach deeply into the soil for remaining moisture.

If you want them only as a soil amendment, then plant and let die.

Peanut is a great crop, because it also can manage a dry spell and continue on if a shower comes.

It also has a bit of trouble with leaves molding during rainy season.

Pumpkin does a good job of covering every little bit of ground area in a sea of leaf.

It requires minimal attention, and the fruit isn't time critical.

when the pumpkins are ripe they will stay for weeks untended.

A can of seed covers a whole lot of ground at the mature stage.

They run and spike, putting roots down from the vine.

I am presently growing

Corn

Mung Bean,

Black Sesame,

Morning Glory,

Spiny Pigweed,

Roselle,

Scattered seed on the ground and let it grow without further tending.

Planted Peanut & Pumpkin in rows

Of course, the native weeds will suffice as well,

if your goal is to increase the carbon content of the soil.

If you want to spread ground cover,

to also increase the carbon while holding moisture in the soil,

I receive free every day a pickup load of coconut coir,

as it is a disposal problem for the coconut merchant.

Spread it on the ground as deep or shallow as you like,

and walk away.

Rice Hull and Corn Cob much the same.

I have to pay for Corn Cob, but only B0.30/kg

A metric ton for B300 if I haul it myself.

The granary would deliver a 7 ton six wheel load for B0.10 freight

on top of the B0.30 material cost => Total B0.40/kg

B2,800 for the whole thing.

My time should be worth more than B100/ton,

so I do it only as I pass by on the way to the farm.

[jamescollister]

Best I have found is corn or chilli seems to do the soil a lot of good and ergo the young trees. Jim

[fremmel]

Gonsalviz it sounds like your rubber is doing well. Good luck. I'm not trying to farm ambitiously enough to raise a cash crop. I just want something to help the land along and cut down some of the problems.

Drtreelove, I followed the weed control thread when it was active because I have a small orchard too that I'd like to not have to mow so often. Mine's not much more than a rai so it's not too big a problem. I've been playing with perennial peanut as a cover crop there but it's not yet spreading as fast as I'd hoped.

Most of the suggestions in that and other threads I've seen are for annuals and seem to be more appropriate to field crops since they have to be cut or disced in and replanted frequently. Last spring we went to the land development office to ask about green manures. They weren't terribly knowledgeable but they did give us 50 KG of jack bean. That wasn't enough for 14 rai but was enough to try it out a little. They sprouted in 2 or 3 days and grew well. We disced most of them under when we planted the rubber but a few survived and we let them grow. They got pretty big but kind of woody and I'm not sure how they'll do during the dry season. According to the tropical forges site the mature plants have a good root system and can be used for erosion control. The ones I've pulled up didn't seem that extensive but maybe they weren't old enough.

WatersEdge, your tip about the beans may well be why I haven't seen anything about them being used in rubber fields. Regarding some of the other possibles, I'm hoping to end up with a legume type for the nitrogen benefit. Like you say, there's lots of things to try but rubber's been commercial for so long that surely someone else has done all the work and I can just tag along.

From reading, pueraria phaseoloides seems to be a very popular rubber field cover crop. It's common name is kudzu and that's a little scary because I'm from north Florida and have seen kudzu take over roadsides and grow straight up over the pine trees. But when used as a cover crop it looks like it should be cut every 3 months and spread as mulch so I guess that keeps it from being too aggressive.

Our dry season is so long and hard here that I suppose anything I plant is going to compete with the rubber for water. I have considered irrigation but that's not something to be entered into lightly even if my 14 rai is small by rubber field standards. But, that's a topic for another thread after I sort things out a little better and find out the tree's water requirements, possible pipe runs vs plowing paths, the head I'll need to pump, operating costs, etc., etc.

[Gonsalviz]

Gonsalviz it sounds like your rubber is doing well. Good luck. I'm not trying to farm ambitiously enough to raise a cash crop. I just want something to help the land along and cut down some of the problems.

Drtreelove, I followed the weed control thread when it was active because I have a small orchard too that I'd like to not have to mow so often. Mine's not much more than a rai so it's not too big a problem. I've been playing with perennial peanut as a cover crop there but it's not yet spreading as fast as I'd hoped.

Most of the suggestions in that and other threads I've seen are for annuals and seem to be more appropriate to field crops since they have to be cut or disced in and replanted frequently. Last spring we went to the land development office to ask about green manures. They weren't terribly knowledgeable but they did give us 50 KG of jack bean. That wasn't enough for 14 rai but was enough to try it out a little. They sprouted in 2 or 3 days and grew well. We disced most of them under when we planted the rubber but a few survived and we let them grow. They got pretty big but kind of woody and I'm not sure how they'll do during the dry season. According to the tropical forges site the mature plants have a good root system and can be used for erosion control. The ones I've pulled up didn't seem that extensive but maybe they weren't old enough.

WatersEdge, your tip about the beans may well be why I haven't seen anything about them being used in rubber fields. Regarding some of the other possibles, I'm hoping to end up with a legume type for the nitrogen benefit. Like you say, there's lots of things to try but rubber's been commercial for so long that surely someone else has done all the work and I can just tag along.

From reading, pueraria phaseoloides seems to be a very popular rubber field cover crop. It's common name is kudzu and that's a little scary because I'm from north Florida and have seen kudzu take over roadsides and grow straight up over the pine trees. But when used as a cover crop it looks like it should be cut every 3 months and spread as mulch so I guess that keeps it from being too aggressive.

Our dry season is so long and hard here that I suppose anything I plant is going to compete with the rubber for water. I have considered irrigation but that's not something to be entered into lightly even if my 14 rai is small by rubber field standards. But, that's a topic for another thread after I sort things out a little better and find out the tree's water requirements, possible pipe runs vs plowing paths, the head I'll need to pump, operating costs, etc., etc.

I don't grow the corn. The brother in law does. He tends the trees and fertilizes them for use of the land.

Edited October 15, 2010 by Gonsalviz

[drtreelove]

I don't know about specifics for rubber. And I don't have experience with the downside of beans that was mentioned. I grew jack beans in mango and lamyai orchards during the rainy season and it all seemed good.

Generally, there is a big difference in approach with a 'green manure' planting vs an inter-crop. With green manure you usually want to cut or disc before it goes to seed to take advantage of the maximum tender bulk organic matter of the cover plant; with jack beans that is at about 60 days after germination. If you let it go longer it will get woody and hard to cut. (An exception is when you let a portion of a field go to seed for your own seed stock for next season.) With green manure you are growing solely for improving soil fertility, so the legume makes more sense for conservation of nitrogen.

If you grow an inter crop, you have to harvest the product, so your incorporation into the soil of crop residue is dependent on the harvest timing. With an inter-crop you are making use of the available soil space to get an additional crop in while your trees grow. The improvement in soil fertility will be secondary or can even deplete net soil nutrients. Bulk organic matter for soil improvement depends on the crop residue available for incorporation and how you handle it.

[JungleBiker]

They use stylo in southern china where the conditions are not so different from here.

See: Stylo in China: a tropical forage legume success story www.tropicalgrasslands.asn.au/.../Vol_39_04_2005_pp215_215.pdf

You can buy seed of an anthracnose resistance variety from the university of ubon ratchathani

I have grown it in my own garden in Khon Kaen for several years without any problem (sowed just one time).

Send me a PM if you need a contact name and email address.

Best regards,

JB

[fremmel]

Thanks, I hadn't thought about stylo for the rubber. Around the first of the year we planted stylo, the hamata - verano variety (locally called thua hamata), as a cover crop for a few rai we've left fallow. That's a pretty dry time of the year but we had a tractor doing some other work so we had him plow the weeds under and we planted that. Not too much came up until we got some rain. It's done OK but it's had a lot of competition with the local grasses. Two or three weeks ago I cut a rai or so with a brush cutter and it's coming back up pretty thick but not thick enough to block the other grass yet.

The tropicalgrasslands site was interesting and there was an article just below that one about it's use in Thailand. From those papers and a few others I read it looks like the stylo can be used in young rubber fields where you want something that will produce good forage and will improve the soil some too. This may be a good stopgap to plant this week while I continue looking for a long term crop. I can cut it back periodically and let it regrow and not have to plow and replant.

Today I finally found a legume cover crop that's drought tolerant and looks like it has been used successively for rubber in Thailand. It's calopogonium caeruleum (thua saelulium), a relative of the calopogonium mucunoides (thua karopo) that's used in south Thailand. Thua saelulium is more drought, shade, and cool weather tolerant but slower growing. Still a lot to learn about it but it looks promising. There's a write up on it here.

[sudyod]

We have 25 rai of cassava that will be harvested by March/April and we would like to plant rubber trees. Is it worthwhile to plant some beans as green manure and then plow them in after 1-2 months or just plant the rubber trees straight away and grow beans alongside? The difference being the green manure, if planted alongside rubber trees, won't get plowed under. Around here it seems people kill off whatever is growing then sprinkle some rice straw around the new trees to help retain moisture. Doesn't make a whole lot of sense but what do I know?

[IsaanAussie]

We have 25 rai of cassava that will be harvested by March/April and we would like to plant rubber trees. Is it worthwhile to plant some beans as green manure and then plow them in after 1-2 months or just plant the rubber trees straight away and grow beans alongside? The difference being the green manure, if planted alongside rubber trees, won't get plowed under. Around here it seems people kill off whatever is growing then sprinkle some rice straw around the new trees to help retain moisture. Doesn't make a whole lot of sense but what do I know?

Sudyod,

Since you will be disturbing your soil a lot removing the cassava it would be a great time to get the ground prepared for the rubber trees and grow a cover crop to get some nitrogen into the ground. I have no experience with either cassava or rubber but am learning a lot about organics and soil remediation. I am planting mung beans on a small patch as the first step on changing spoil into soil. Some good fungal compost under each tree will get your rubber off to a good start. I make mine from pig manure and rice wastes. Germination tests of seeding the mung beans in compost have had great success. Soil drenches made from compost and from vermicompost are brillant and avoid chemical fertilisers.

As for the time involved waiting for the rubber to grow, have a look at succession planting a range of crops as a canopy cover develops. Vanilla or coffee would be great cash crops to grow under the rubber ultimately, but in the mean time the land should return as much as possible.

Isaan Aussie

[sudyod]

Hi Isaan Aussie,

Do you know anyone growing coffee up around Loei? I didn't even think of it as a possibility since I haven't heard of it grown here. If it will, great...I've always wanted to grow, roast, grind and brew my own gahfee.

With the green manure, I'm thinking of planting beans at the same time as the rubber. I think that's the current thinking around here. It would get plowed under I presume in the dry season after the beans are harvested, or in the following rainy season before planting corn or more beans. I have heard it is better not to grow cassava with rubber as it depletes nutrients the rubber trees require. I would like to follow you in trying to use compost etc and reduce dependence on commercial fertilizers, trouble is I have only enough compost for my small veggie plot in the yard. I had big plans to set up a large composting facility demonstrated by a Thai university I saw online, but just haven't gotten to it.

Somehow the days fill up with assignments, it gets dark, and then the village turns in for the night.

Mike

[IsaanAussie]

Hi Isaan Aussie,

Do you know anyone growing coffee up around Loei? I didn't even think of it as a possibility since I haven't heard of it grown here. If it will, great...I've always wanted to grow, roast, grind and brew my own gahfee.

With the green manure, I'm thinking of planting beans at the same time as the rubber. I think that's the current thinking around here. It would get plowed under I presume in the dry season after the beans are harvested, or in the following rainy season before planting corn or more beans. I have heard it is better not to grow cassava with rubber as it depletes nutrients the rubber trees require. I would like to follow you in trying to use compost etc and reduce dependence on commercial fertilizers, trouble is I have only enough compost for my small veggie plot in the yard. I had big plans to set up a large composting facility demonstrated by a Thai university I saw online, but just haven't gotten to it.

Somehow the days fill up with assignments, it gets dark, and then the village turns in for the night.

Mike

Sorry cant help with Loei. I would look more towards vanilla considering the limited spacing of rubber trees, perhaps pepper could be an option, anything that will grow on a trellise in shade. The real issue is getting the ground ready for rubber and that means something that will improve the soil NOW. On the volume of compost and the facilities needed, wow big issue. I currently have only a small number of pigs about 3 wheelbarrows of contributions a day and turn out about 8, 60litre bags of compost every 3 to 4 days. For me the compost sales contribute to the cost of feeding the pigs, so you could argue that under current price/cost regime, I make more recycling excrement per pig than selling the pig. My facilities are basic, six by 2 cubic metre boxes and a pitch fork. I used to have cows but gave up, so now I walk to work at the pigsty and every few days take a wheelbarrow and shovel after the village cows are taken out to pasture and pick up the worms dietary requirements, for free.

Yes my day is full of do right nows too. I am always walking home past the rest of the village who are already showered and relaxing out front of their houses as darkness falls, very peaceful end to the day. There is always tomorrow!

Isaan Aussie

[fremmel]

For what it's worth, I decide to go ahead and plant sunn hemp as a short term cover crop this year. I sowed it right after I had the rubber field plowed to turn under the weeds at the end of October. I didn't replow to cover the seed and had mixed growth with some areas coming in really thick and some kind of sparse. I let it grow until there was good crop of flowers and then plowed it under about 3 weeks ago. The sunn hemp roots had good nodules and and since it grew to about 1 1/2 m high there was a lot of bulk to plow under so hopefully I did some good.  

I found a good outlet for the sunn hemp seed that's not to far from you Sudyod. About 20 km west of Nong Bua Lampu off the road to Loei. The store's number is 081-965-2137 and in October he was selling the seed for 25 b/kg.

[sudyod]

Fremmel, why did you choose Sunn Hemp over beans? Are your trees a few years old? I guess my question is really this... is it worthwhile to use up 2 months of rainy season growing green manure before planting rubber trees or get the trees planted and then grow beans or hemp after? I want the trees to get off to a good start and think money spent at this stage is money well spent. The differences in tree size and uniformity is striking between neglected and well maintained land. I would imagine tapping a year earlier would recoup these initial expenses.

IsaanAussie, interesting commentary on values you have initiated by comparing pig poop with pig. I think I'll be pondering that for the rest of the day! lol! Have you posted any pics of your farm? I would like to see it.

Mike

[fremmel]

I just planted the rubber this year. I decided to plant sunn hemp for a couple of reasons. 2 or 3 people here reported that they'd had good results with sunn hemp, I found a good source for it near by, and the seed was cheaper than the bean seed I found. Also, my wife was a little worried that the local foragers from the neighboring village would see the beans and come gather them at night and maybe step on some trees.

This is my first time planting trees so I don't really have the experience to tell you if the benefit of the cover crop is worth planting 2 months late. I would guess not but it's just a guess. On my land I wouldn't have been able to do that anyway. The ground is too soft for a tractor after the rainy season gets going. If yours isn't too soft, maybe just planting the rubber and then sowing the cover crop between the rows would be the thing to do.

[jamescollister]

Fremmel, why did you choose Sunn Hemp over beans? Are your trees a few years old? I guess my question is really this... is it worthwhile to use up 2 months of rainy season growing green manure before planting rubber trees or get the trees planted and then grow beans or hemp after? I want the trees to get off to a good start and think money spent at this stage is money well spent. The differences in tree size and uniformity is striking between neglected and well maintained land. I would imagine tapping a year earlier would recoup these initial expenses.

IsaanAussie, interesting commentary on values you have initiated by comparing pig poop with pig. I think I'll be pondering that for the rest of the day! lol! Have you posted any pics of your farm? I would like to see it.

Mike

If you are going to plant and not pot the trees for a few years, get them in the ground at the first good rain. Young trees take time to get going and if you plant late the trees will not start the growth spurt before the dry comes and many will die if you can not water. Jim

[sudyod]

Hi James,

I will do that. Give them the most rain and a chance at surviving dry season. It makes the most sense. After reading a lot of posts, I think I'll get some beans going later on towards the end of rainy season. By then the trees will be better rooted and maybe a little taller than the beans.

Still interested in Sunn Hemp too but don't know how it compares to the red beans grown around here when it comes to nitrogen fixation.

Mike

[sudyod]

Hi Fremmel

Sorry, I missed your post. Those sound like good reasons, particularly the one about stepping on trees while swiping your beans! I've got too much time right now to read about this. I'm not trying to reinvent the wheel, but like to look for better ways to do things, much like yourself and others posting on here. Often, I find in the end, the current method is the best. Or, in Thailand, the current method is the current method because it is the current method.

I will still try to slip in a sack of Sunn Hemp when that time comes and hope it's a winner.

Mike

[sudyod]

Reading what looks like a well written article on Sunn Hemp. With my current internet, TOT hi speed, should be able to read the rest of the paper sometime next week.

http://assamagribusiness.nic.in/Sunnhemp.pdf