Food for All - Agri-culture: Reconnecting People, Land and Nature - page 97

irrigated rice cultivation, and produces such extraordinary productivity
increases, that most professionals have elected to be sceptical.
The system is centred on making better use of the existing genetic
potential of rice. Firstly, rice seedlings are transplanted after 8 to 12 days,
instead of the normal 30 to 50 days. Early transplanting increases tillering,
and SRI plants typically have 50 to 80 tillers, compared with 5 to 20 for
conventional ones. Each tiller bears a head of grain. Secondly, rice
seedlings are usually planted close together in order to minimize weed
infestation. But in the SRI, they are planted at least 25 centimetres apart
in a grid pattern rather than in rows. This facilitates mechanical weeding,
as well as saving on costly seed - the system uses about 7 rather than 100
kilogrammes of seed per hectare. More widely spaced plants develop a
different architecture, with more room for roots and tillers; and better root
systems mean reduced lodging (ie, the likelihood of stem weakness and
collapse).
Most scientists and farmers believe that rice, as an aquatic plant, grows
best in standing water. In the SRI, however, paddies are kept unflooded
during the period of vegetative growth. Water is only applied to keep the
soil moist, which is allowed to dry out for periods of three to six days.
Only after flowering are paddies flooded. They are then drained 25 days
before harvest, as with conventional rice. Such management encourages
more root growth. Since flooding is the conventional approach to weed
control, SRI farmers must weed up to four times - mechanically or by
hand. Farmers who do not weed still get respectable yield increases of
twofold to threefold. But those who weed get increases of fourfold to
sixfold. SRI farmers also use compost rather than inorganic fertilizers.
The proof that SRI works comes from the number of farmers using
it - an estimated 20,000 farmers have now adopted the full SRI, and
Sebastien Rafaralahy of Tefy Saina estimates that another 50,000 to
100,000 farmers are now experimenting with elements of the system.
Cornell scientists led by Norman Uphoff have helped research institut-
ions in China, Indonesia, the Philippines, Cambodia, Nepal, the Côte
d'Ivoire, Sri Lanka, Cuba, Sierra Leone and Bangladesh to test SRI. In
all cases, severalfold jumps in rice yields were achieved. In China, for
example, yields of 9 to 10 tonnes per hectare were achieved in the first
year, compared with a national average of 6 tonnes. 31
Salinity Farming in Vietnam
It takes a sharp eye and an open mind to see the possibilities in complex
systems. Vo-Tong Xuan of Angiang University has both of these, and he