Wednesday, November 16, 2011

Weed control in natural rice farming

These are the important aspects in weed control in natural rice farming. This is the summary taken from 'One straw revolution' and some from others experience and some taken from my own experience. I haven't mastered these techniques yet, but think these are the things to be taken care of.

1. No-tilling - Tilling brings out the buried seeds back to surface and this has better germination capacity. So without tilling, seed resources on the field will be exhausted and hence weed population will decrease eventually. But there are other sources of seeds like rain water, wind etc. Flooding of rain water from other fields has to be prevented for better weed control.

2. Mulching - Mulching with remains of previous crop reduces weed, since mulching does not provide sunlight and hence the weed population decreases. Considerable amount of mulching will be required for better weed control. So when you are staring, mulch with as much as you can. Twigs, branches etc..provide good mulch and weed control.

3. Leguminous cover crop before - Have a leguminous cover crop in the field before planting grain and it is said that grass varieties does good in leguminous cover crop. If the grain is sown in leguminous cover crop, and then cover crop is cut and mulched, good weed control can be assured.

4. Leguminous cover crop along with rice - If there is another cover crop which grows along with grain, it is the best. Like Fukuoka san used clover along with rice. Clover does not interfere with rice, and if it takes control flooding the field weakens the clover and once the rice takes over, clover will grow beneath the rice. Once the clover is weakened and rice comes out, he later Fukuoka drains water so that clover again establishes underneath. This kind of water control is required to control the cover crop. Clover does not grow well in all the climates, so for each region a suitable cover crop has to be found out.

5. Rice that can compete with weeds - Rice also was a wild growing variety in the past, but after cultivating in controlled environment with all the extra care, they are no longer wild. But while selecting the rice, if we can use the variety which is not hybrid, rather local variety they will compete with weeds more effectively. See the video - where Thiru. Karikalan explains his rice cultivation using local variety called 'Kattuyanam'. This takes 6 months to mature and grows 7 feet tall. It is pest resistant and gives good yields without applying any manure. Till 1 feet there will be weeds, afterwards the rice still grows tall and weeds loose the competition. This variety is supposed to be drought tollerant as well as flood tolerant and has medicinal values.

Fukuoka san used a variety which he had developed called Happy Hill. According to his words in Natural farming book.

"I have created, together with the insects in my fields, a new strain of rice I call
"Happy Hill." This is a hardy strain with the blood of wild variants in it, yet it is also one of the highest yielding strains of rice in the world. If a single head of Happy Hill were sent across the sea to a country where food is scarce and there sown over a ten- square-yard area, a single grain would yield 5,000 grains in one year's time.". Not able to find the source of its seeds, so if anyone knows please report back. - According to the following source..these are the variants of the Happy Hill rice..

Fukuoka invented and registered three varieties of rice.
Fukuoka 1 gou(Fukuoka No.1)-fast growing,
Fukuoka 2 gou(No.2)-late growing,
Fukuoka mochi 3 gou(glutinous No.3).
There are not much information available on this, but it is said to have wild strains in it.

6. Timing of crops - Depending on the season, the crop should be sown, so that it emerges first before the weeds. For e.g in kerala, weeds will start emerging heavily as the rain starts. Before the weeds start germination, rice should be sown and established. Once the crop is established, later weeds won't come that easily. A few sentences from 'One Straw Revolution' - Coping with Weeds - If seeds are sown while the preceeding crop is still ripening in the field, those seeds germinate ahead of weeds. Winter weeds sprout only after the rice has been harvested, but by that time winter grain already has a head start. Summer weeds sprouts right after the harvest of barley and rye, but the rice is already growing strongly. Timing the seedling in such a way that there is no interval between succeeding crops gives the grain great advantage over the weeds.

7. Continous coverage - Once the field is left uncultivated after a season, weeds take over. It is better that field is continously used for one crop or other. When there is no crop, better to use a cover crop so that there is no chance for weeds to emerge. Again, depending on climates, the cover crop for that region has to be selected.

8. Crowding out weeds - The crop should be planted dense so that it can crowd out the weeds. In my first rice planting experiment, I maintained 1 feet distance between seedlings and weeds came up strongly in the vacant spaces. This kind of distance may be OK for SRI rice, since there field is completely ploughed and seasoned so that weeds are not given a chance at all. But in natural farming, we have to crowd out weeds using crops.

9. Allow weeds to germinate in summer - In one of the book Fukuoka san mentioned to water the area in the summer so that weeds germinate and then stop the watering, and weed seeds gets destroyed.

10. Weeder Ducks. Fukuoka used ducks to control weeds in his rice paddy in the initial days. The following link also talks about this. Ducks don't eat rice, but young weeds, may be this is applicable in transplanted fields where the rice plants are more mature.  Links -

11. Consideration for weeds - As some body told, weeds are sown by god and crops by man. Control weeds only when it tries to control your crop, otherwise allow it to grow, change your attitude towards weeds.


sonney said...

dear nandakumar,

nice article. which cover crop is best suited for kerala weather , especially for places with minimum rainfall? what is the name for clover in malayalam? am a farmer trying out new e mail id -
pl msg if possible. regards and best wishes.

Nandakumar said...

Hi Sonney,

Thanks for the comments. Sun-hemp seems to be good, it produces lot of bio-mass and germinates well in kerala weather. Farmers conventionally use daincha also. Other cover crops are cow pea, horse gram etc..

Don't know name of clover in malayalam, it is said to be growing in cold climates, but wanted to give a try.

Will contact you over the email.


Raisa said...

Nice .Quite happy to read this .I have been struggling with the methodolgy with out proper support but I beleive in it

Nandakumar said...

Hi Subhanallah,

Thanks for comments.

Would like to hear about your experiments too. There is always something to learn from different experiments.


Raisa said...

There is a particular plot in my work place and that particular part is not ploughed till date right after the rice harvest in may 2011.
I planted balck beans and brown beans along with many different vegetables ,But The beans was quite dominating and took over the whole field.We infact got a good harvest of beans from it but we lost all the veggies .Now this may I sowed the same beans and intercropped with yam , onions , brinjal and another kind of bean (koththu avarai ).
Now though lost some in th eheat of summer , I still have some of them growing in the farm .
When i walk over the land I can feel that the land is not even now It has many ridges and furrows but underneath a thick grass cover .It is interesting and amazing to see that particular area .Any idea is it suppose do be like this ?
I want to grow ric ein this part as now I think the soil is rich .In this case should I disturb the ground cover and sprinkle seeds/seedballs .or just throw the seedball directly ?.Plz suggest me if you have ideas any .Thank you !

Nandakumar said...

Hi Subhanallah,

This is an interesting experiment !!!. After growing legumes, it looks like land has become rich. Ridges and furrows may be made by rats, this happens in my rice field, especially since the field is not flooded.

If there is thick mulch, then putting seed/seedballs above it may cause bad germination. Typically seed/seedballs are put above the standing crop, so that they touch the ground. I think this is essential for good germination.


Anonymous said...

Very informative. thank you.

Puliyarla [ Oxalis corniculata] is very similar to Clover. Since it is a weed I'm not sure how one can seed large areas for ground cover.


Nandakumar said...

Thanks for this information about Puliyarla, it looks to be a herb widely used in Ayurveda. But this does not look to be leguminous which is the recommened cover crop.


Matthew Arnold said...

Im confuse, if we did not till the field, didn't rice from the previous crop grow back, so basically defeating our seedling, isn't it?

Nandakumar said...

Yes, this is true to some extend. But natural farming recommends crop rotation and hence this is not an issue. I haven't mastered this, but planning to grow pearl millet, finger millet after rice, in these cases a few rice seedlings won't be an issue.


Unknown said...

So did you manage to plant clover? I am also considering clover as a cover crop to enrich some land left fallow, but am worried that it may not survive our long dry months. Where are you getting the seeds from?

Nandakumar said...

One of my friend in Japan had sent some white clover seeds, but it didn't even germinate in this climate. It looks like, it need much colder climate. My search for a proper cover crop for rice still continues. I am planning to use green gram, moth beans as trial run. Also recently I found that Alice clover grows here and there in my farm.

Nice to hear from some one who is also planning to use clover as cover crop. Where are you located?