Applied Geography formerly Rural Training Center, Thailand

2007 Oct 31 53% Increase in 2007 Rice Harvest

Oct 31, 2007

The rice harvest is complete. The final tally is a whopping 53% increase over last year?’s harvest!
Traditionally, Thai farmers assess their farm situation on the basis of having enough land to produce enough rice to feed their family for 1 year. By that standard we needed to acquire more rice paddy land. But our fundamental belief was to reduce the pressure to clear more land for agriculture as this contributes to deforestation and increased soil erosion as well as other environmental issues. Our approach has been based on improving the soil to increase yields without the need for more land and more labor.
Under the direction of our farm manager Aoi, this year?’s increased rice harvest is due to the application of low cost / low tech / no tech methods such as adding compost and other organic soil enhancements (e.g. EM bacteria and green manure). This did not employ any new technology or knowledge. These techniques are well known from the past. For various reasons, many older practices seem to have been lost, ignored, or pushed aside by more modern practices.
We only get one wet rice crop per year (with the monsoon rains). At the end of last year?’s rice harvest, the stubble was left in place. When it was turned under, it became compost. Normally, we would grow a dry crop in the rice paddies. But this year, due to other family matters, the rice paddies were left fallow.
In early April 2007, Aoi began the preparation for planting the rice. She started by plowing the rice dry paddies. Mung bean (Vigna radiate formerly cited as Phaseolus aureus or Phaseolus radiatus) seeds were manually broadcast in the dry paddy land as a green manure. As a legume, nitrogen fixing is the key function we sought as a means to improve the paddies. In about 6-7 weeks, the mung beans matured to a height of about 60 cm / 2 ft. About 20 L of liquid EM bacteria was applied to the dry paddy land. Aged manure from our cows was applied. Then everything was ploughed under to compost in place. The paddies are then irrigated so they could be smoothed and ready to have the rice transplanted.
The simplicity of this approach makes it easy for others to implement. All of the materials we used are readily available off the shelf. Aoi made two different batches of EM bacteria (kits are available in almost every farm supply store). One batch was made entirely of vegetable kitchen scraps. Another batch was made using fish and fish parts from the fish ponds and kitchen. The liquid from the EM bacteria tubs was poured through window screen fabric to remove the chunks. This would prevent clogging the sprayer. The liquid from both batches were mixed together and then applied to the rice paddies.
The common problem with tropical soils is low nutrients. The high temperatures and high moisture of the tropics tends to accelerate the decay process. Heavy rains wash nutrients away before they have a chance to move downward into the soil. So it is important to get more organic material into tropical soils in order to successfully farm them.
About the time Aoi was planting the mung beans, the rice seedling nursery bed was started. The family tradition has been to pick a plot of dry ground outside the rice paddy area. Preparation was minimal. The soil is turned by simple hand tools. The rice seeds are planted using a dibble stick (a pointed stick used to make a shallow hole in the soil for seeds). The idea is the plant the paddy rice seeds in dry land. This ?“harsh?” environment forces a sort of ?“natural selection?” in that the hardiest of the seeds germinate to produce hardy seedlings. While growing, the rice nursery bed isn?’t very pretty. The seedlings are pale green to yellow as though on the verge of dying off.
When it was time for transplanting the rice, the seedlings are uprooted, tied into small bundles, and the tips of the leaves are trimmed off. The idea is to reduce the leaf area and thus cut down on evapotranspiration and stimulate plant growth when the seedling is transplanted.
The combined effects of a harsh nursery bed and reduced leave area seems to make the rice seedlings very appreciative of being transplanted into the paddies where they get all the water they want! Casual observation over the years convinced the family that this approach produced seedlings with stronger stems than if they had started the seedling nursery in a wet paddy. Once transplanted into the organically enhanced soil and given abundant water, the seedlings took off!
In about 5-5 ?½ months, the rice will be ready to harvest. As the panicles form, pest control can become a concern. The family never used synthetic chemicals on the farm. But this year, Aoi reported there were very few insect pests in the rice. Some people feel that insects only attack weak plants and avoid healthy ones. We can?’t attest to this, but the health of our rice this year was a focus of conversation when the threshing crew came to the farm. As the rice was being harvested, the thresher crew all commented on how our rice was considerably heavier than most others. In fact, one neighbor directly adjacent to us had a very bad year. The rice in his fields did not really develop well at all. About half of the seeds were hollow and had not developed at all.
In contrast to the 2006 rice harvest, this year?’s yield was up 53%. So without expanding the rice paddy acreage, we now have more than our needed 1 year supply of rice! This was very encouraging news. It reinforces our fundamental belief that low tech, low cost soil improvements can result in increased yields.