Last week we weeded all the SRI plots for the first time. Traditionally, farmers here do not weed their rice fields because keeping a layer of standing water in the field can help suppress some weeds, except aquatic species. Since SRI plots are not flooded and there is plenty of space between the rice plants, weeds are able to establish and have much access to sunlight. These plots are soon populated by weeds.
Apparently, we have got a lot of weeds in the SRI plots:
While in the traditional plots, weeds have not come out yet:
One thing to notice is that the traditional plots were planted 2 weeks later than the SRI plots. This means that the soil in the SRI plots has not been disturbed for longer time than in the traditional plots, which favored weed seeds germination and growth as well.
To minimizing manual labor and herbicide input, many SRI farmers around the world use mechanical weeders to keep the weeds down. These are mostly simple equipments that are invented by innovating farmers and are easy to use and maintain. Here is a manual of some popular weeder models. We have bought a cono weeder from the Taiwanese and then tried it in our SRI plots last week.
Details of a cono weeder:
How it works: