tropical cover crop

[Gerry]

Does anyone know of a green manure cover crop such as vetch that is suitable for a tropical climate? I am looking for something that would work in the rice fields of Thailand. Thanks.

[Katra]

Aren't rice fields flooded? So you would need a water plant? What about cress? And that could be a secondary money crop as well.

K.

[Gerry]

Yes the fields are flooded, but only the part of the year that the rice is actually growing. I have heard that in Viet Nam some farmers use blue-green algae to add nitrogen to the soil at this stage, but I can't confirm if that is true.

The time that the fields are fallow in the farms I am thinking of in Thailand is during the dry season. It doesn't rain for months and it is really quite hot, especially in the sun as these fields are. It is quite a different set of circumstances from when I plant hairy vetch in my garden for the winter in New York!

Anyway, thanks for the tip on cress. I will look into that. Meanwhile does the new information about the conditions bring any ideas to anyone's mind?

Thanks

Katra wrote:

[Katra]

Alfalfa?

That is a legume crop so would add nitrogen back to the soil, and is very valuable as a livestock feed. They used to grow it when I lived in California in the Mojave desert. Might need some irrigation, but should not be too bad.

I'm interested in hearing ideas from others. ;-)

K.

[simy1]

I don't eat the watercress off the creek at the end of my backyard, and I live in suburban Ann Arbor. Cress from a tropical rice field? liver fluke galore (or worse).

[Katra]

Well... Liver fluke comes from eating raw fish. :-) I don't think you can get it from eating the cover crop?

I know that horses can get it from eating the eggs, but I think it needs an intermediate host for humans. The life cycle is rather complex.

The greens would just need a thorough cleaning.

I doubt that it'd be exported anyway.

K.

[nswong]

In I'm not wrong, Alfalfa are not for tropical.

[nswong]

farmers

In Malaysia, the most popular legume cover crop I think should be Calopo(Calopogonium mucunoides) and Butterfly Pea(Centrosema pubescens).

Both of them are drought and flood tolerance. Butterfly Pea are more drought tolerance, Calopo are more flood tolerance. As legume they are slow to start, and the organic matter they produce are not in long lasting form. For what I notice, nearly all rice field are heavy clay soils, since Butterfly Pea grow well in heavy clay soils, it may be the better choice.

For fast growing and longer lasting organic matter, you have to look for grass cover crop.

I suggest you try this: After you harvest and drain, spread a four inches thick rice hull on the rice field and till it in. Volunteer rice cover crop will grow from the rice hull you till in. When the weather are getting dry, till in the rice cover crop, wait for two weeks, seed the Butterfly Pea and Calopo mixed, let the result to decide next time will goto either Butterfly Pea or Calopo. Please put in mind that, you have to seed before it's really dry, both legumes need rain to germinate and grow their root to deeper part of soil in search of water.

The advantage are: Rice hull are free. Rice hull do contain long lasting organic matter. Rice hull will supress other weed but provide volunteer rice cover crop from the rice that mixed in the rice hull.

BTW: The volunteer rice cover crop can grow without under flood or irigation, but they will not produce good crop for harvest, this is my personal experience.

[simy1]

you get it also from water contaminated from animal waste, and of course in third world countries a large percentage of crops is waste and sewage fertilized. Not too many green salads in the tropics. they like their veggies with a thick skin, and/or cooked.

[Katra]

Well, it was said that the weather was hot and dry, and alfalfa grew in the desert....

Oh well! Just tossing out ideas!

So what good is vetch? I'm always trying to think of commercial crop value.

K.

[Katra]

Damn. I did a quick google search and you are correct! :-P Time to go back and brush up on my parasite life cycles. I'm supposed to know this stuff!

(eating crow.....)

[B.Server]

Alfalfa is not a very likely to be a candidate. It requires a LOT of water and was likely grown in the Mojave in winter with highly subsidized irrigation water. If the Thai's had "free" water, they could grow a number of things, non least of which would be a second crop of wet rice.