There is a rice growing system called SRI.
SRI = System of Rice Intensification
It needs very low water quantity compared to traditional system .
SRI is not related to SRI Lanka.
As per Wikipedia, SRI is a low water, labor-intensive, organic method that uses younger seedlings singly spaced and typically hand weeded with special tools. It was developed in 1983 by the French Jesuit Father Henri de Laulanié in Madagascar.
Mr. Salinda Dissanayake MP, as a farmer, is an expert in Sri Lanka about this system. He was talking about this with un even in 1990s and practicing this in his own farm for decades now.
As per records he got 17 tons/Ha from BG358 (340 bushels / acre)
Unfortunately officials in Agri Dept. worked against it or didn't give any support.
Only problem in SRI method is it is labour intensive. You need lot of manpower for planting and managing the crop. Hence we find it difficult to get the farmer support to do it in acres of lands they have. For small land lots SRI is perfect.
Rice yield is always increased when there is less water. Normally our farmers want to submerge the field with water during entire growth period. The rice plant is NOT an aquatic plant. It sucks air Oxygen from roots. If you keep it's rootzone fully under water, the plant experience breathing problem, like asthma for us. ගොයම් යනු ජලජ පැලෑටියක් නොවේ.
Farmers never agree on this. They like to see water running all over the paddy fields, every time.
But, even in our major schemes, whenever there was moderate water scarcity, the harvest increases significantly than the seasons where we had ample water supply.
In SRI method they keep the soil in moist but not under water. This gives much needed Oxygen to produce bigger harvest . But unless all the farmers in the area corporate for SRI, you cannot keep excess water out from your area.
As reported in international publication,
SRI in other countries
Many countries reported remarkable
increases in yield. Salinda
Dissanayake, Member of Parliament
in Sri Lanka, personally tested SRI in
his own rice field of a little more than
2 acres for four seasons, using seeds
of various varieties. He got the highest
yield of 17 t/ha with BG358, a variety
developed by the Sri Lankan rice
researchers. Even with local varieties
such as Rathhel and Pachdhaiperumal,
usually much lower
yielding at ~2 t/ha, impressive yields
of 8 t/ha and 13 t/ha were obtained.
Dissanayake formed a small group
to inform farmers of SRI; and farmers
who took up SRI from 18 districts
have doubled their yields on average.
"These yields were obtained with
less water, less seed, less chemical
fertilizer, and less cost of production
per kilogram …among SRI users, we
find people of many different income
and educational levels and different
social standing, including many poor
farmers having only small plots of
land, farmers with moderate income,
some agricultural scientists, and a
few administrators, businessmen and
political leaders who practice it with
their own convictions," Dissanayake
H. M. Premaratna, a farmer from
the Ecological Farming Centre,
Mellawalana, Sri Lanka, backed up
the enthusiasm of his Member of
Parliament, and has personally provided
training on SRI to more than
3000 farmers by 2002. "From my
experience, I have observed that the
rice plant becomes a healthier plant
once the basic SRI practices are
adopted," he said.
Reports from 17 countries in 2002
showed that three-quarters of the
cases gave a significant yield advantage
of at least 20 to 50% increase,
and although the super-yields reported
from Madagascar have not been
obtained elsewhere, some farmers in
Cambodia and Sri Lanka have come
close. Overall, the conventional systems
yielded 3.9 t/ha, very close to
the world average for rice production.
The average for all the SRI yields
reported was 6.8 t/ha