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2014-05-13 09:47:18
Another green revolution is stirring in the world s paddy fields
A SEED of rice that could transform the developing world saved Asha Ram Pal s
farm in the Indian state of Uttar Pradesh in the summer of 2008. Mr Pal had
planted rice on his small plot, not much bigger than a football field. Floods
are an ever-present threat in the state, making it one of the poorest places in
the world. And that year the monsoon was particularly heavy, remembers Bob
Zeigler, director of the International Rice Research Institute (IRRI). Mr Pal s
fields flooded for two weeks after he planted the rice seedlings; a few weeks
later, they were inundated again. He thought his crop was lost. His neighbours
advised him to do what they have always done when the floods come: prepare for
hunger.
But this time Mr Pal had planted an experimental seed developed by scientists
from IRRI in the Philippines. The seed has a genetic sequence bred into it
which puts it into a sort of suspended animation when submerged. Instead of
drowning, Mr Pal s rice sprang back when the water receded. In a normal year he
gets a tonne or so from his 1-hectare (2.5-acre) plot; in a bad year nothing.
In that terrible flooded season, he harvested 4.5 tonnes as good a yield as on
any rain-fed paddy in the world.
Flood-resistant rice is now spreading as fast as the waters themselves. Five
years after the first field trials, 5m farmers across the world are planting
more than a dozen varieties of rice with flood-resistant genes, collectively
called Sub 1 . They are proliferating even faster than new rice varieties
during the heady early days of the first green revolution in the 1960s. And
Sub 1 is the first of a new generation of seeds, says Mr Zeigler. If all goes
well, over the next few years plants that tolerate drought, salinity and
extreme heat will revolutionise the cultivation of mankind s most important
source of calories. But that will depend on the technology working as promised
and, in particular, on public policies that support a second green revolution.
Neither is guaranteed.
The first green revolution helped save the developing world from disaster. Two
plant breeders, Norman Borlaug with wheat and M.S. Swaminathan with rice,
persuaded governments in Asia and elsewhere to encourage the planting of
higher-yielding varieties, especially of rice; 3.5 billion people, half of
mankind, get a fifth of their calories or more from the stuff. When the men
started work in the early 1960s, China was suffering the famine of the Great
Leap Forward. And India was widely thought to be on the brink of starvation.
Today in Asia, famines are things of the past. One reason is the spread of
democracy. Another is the green revolution, which has ensured that there is
plenty of rice India even exports it. And demand seems to be shrinking: the
richest Asian countries, Japan, Taiwan and South Korea, are eating less rice.
This has led governments which once supported the green revolution to think
that a new one would be unnecessary. Rice, they reason, is a problem that has
been solved. Better to improve the diets that are causing obesity or change the
intensive-farming practices that are damaging the environment.
But it is not clear that the mission has been accomplished. In Asia as a whole,
consumption per person is flat, not falling. The population is still growing,
so demand for rice is rising on the continent where 90% of the crop is raised.
In Africa, where a third of the population depends on rice, demand is rising by
almost 20% a year. At that rate rice will surpass maize as Africa s main source
of calories within 20 years.
Seeds of stagnation
As a rule of thumb, if the world s population grows by 1 billion, an extra 100m
tonnes of rice is required to feed them. Given current world-population
forecasts, total rice consumption, now under 450m tonnes, is likely to grow to
500m tonnes a year by 2020 and to 555m by 2035 an increase of 1.2-1.5% a year.
That would be manageable if rice yields were also growing at that rate. But
they are not. They are rising at barely half that pace.
The first green revolution almost doubled yields from 1.9 tonnes a hectare in
1950-64 to 3.5 tonnes in 1985-98. Even that was only enough to keep pace with
population growth: yields and population rose at the same rate (1.75% a year)
in the half century after the green revolution started.
Now the gains seem to have levelled off. Plant breeders fear that, with current
technology, ten tonnes a hectare for rice in intensive-farming systems may be
the limit, though it is not clear why. What is clear is that, out in the
fields, output per hectare is stalling, and in some places falling.
For 25 years, IRRI has been planting a field using its best seeds. The field
itself has remained much the same: the bugs and microbes that live in the roots
of the rice plant mean that soil fertility is maintained even if three crops
are grown each year. But output from the plot has fallen from nine to ten
tonnes a hectare in the early 1990s to seven to eight tonnes now, as pests and
diseases have taken their toll. Rice yields were rising at 2.5% a year between
1962 and 1982. But between 1992 and 2012 growth fell to just 0.8% a year (see
chart 1).
The facts of rice
Without new seeds, yields will decline further. Global warming will tend to
push harvests down: higher night-time temperatures are associated with lower
yields. The richest rice-growing areas in the world are the deltas of Asia s
great rivers, such as the Mekong, Brahmaputra and Irawaddy; they are vulnerable
to rising sea levels and increased salinity, which kills rice. The plant uses
two to three times as much water as other cereals (largely for levelling the
paddies; the plant itself consumes no more than wheat or maize), but water is
scarce everywhere. And each year the spread of Asian especially Chinese cities
converts millions of acres of good rice-growing land into buildings and roads.
The consequences could be momentous. Rice plays a role in Asian societies that
is hard for outsiders to appreciate. (A small example: Toyota means bountiful
rice field and Honda means main rice field .) In the river basins that are
the world s rice bowls, nothing else will grow with the same productivity. It
is rice or nothing, and if there are problems with rice, there are problems
with everything. A rice shortage would have geopolitical implications. No
Indian or Chinese government could contemplate the possibility with equanimity.
They would do whatever it takes to ensure they have enough rice. If this pushes
up world food prices, so be it. If they must twist the arms of exporting
countries, they will. If Asia s giants feel insecure, their neighbours will
tremble.
So a lot is riding on boosting rice yields. But how likely is it that a second
green revolution will take off?
The first was a relatively simple affair, technologically at least.
Conventional rice varieties were long and leggy. If you gave them fertiliser,
they grew too tall and fell over. That changed in 1962, when IRRI released a
dwarf variety called IR8. Because its stem was short, it was able to absorb
fertiliser without collapsing. So now farmers had a crop they could feed. And
with stem growth restricted, more of the increase in plant size went into the
head of seeds (called a panicle). IR8 spread from the Punjab to the
Philippines, transforming farming wherever water could be controlled and
fertiliser delivered.
The second revolution will be different. Farmers will not adopt a single
miracle variety. Instead, researchers will tailor seeds for particular
environments (dry, flooded, salty and so on). And they are also trying to boost
the nutritional quality of rice, not just the number of calories. As a result,
the second revolution will be felt most profoundly in the poorest areas and
among the poorest farmers. In contrast, the first had the biggest impact in the
richest fields, with the most water and fertiliser.
The flood-resistant trait that rescued Mr Pal s crop was first identified in
the 1980s, in a few old-fashioned varieties native to Odisha, another
flood-prone state in eastern India. After more than a decade of false starts,
plant scientists identified the genes that make the Odisha varieties
flood-tolerant. They went back to IR8 s descendants, spliced these genes into
them and bred from the result. Having spent years getting nowhere with
traditional plant-breeding methods, scientists went from marking the genetic
sequence to producing flood-resistant seeds in four short years.
Abdelbagi Ismail, IRRI s principal scientist, hopes to do the same for other
traits that have so far eluded breeders, such as drought resistance and heat
tolerance. High temperatures during rice flowering can lead to sterility. If it
is too hot, the anthers of the plant, which contain the pollen, do not open
properly; the pollen is not released, the stigma are not pollinated and the
crop is lost. The problem occurs during the hour or so when the plant flowers.
It could be overcome if it were possible to encourage rice to flower in the
cool of the early morning as opposed to scorching midday, its usual hour. Tom
Ishimaru, who works at IRRI and the Japan International Research Centre for
Agricultural Sciences, has found a gene which codes for early-morning
flowering, raising hopes of solving the problem.
Such breeding programmes will not have the same dramatic impact that IR8 did.
But developing miracle seeds is not the only way to boost yields. During the
1990s China did it by improving hybrids: crossing different lines to combine
the advantages of both. This is the usual way of improving maize, but it is
less common with rice. Unlike maize, rice breeds true in successive
generations, so farmers can retain seeds from one harvest and plant them for
the next. Farmers will switch if a new variety gives them a big one-off boost,
but not just to get the small increments offered through hybrid improvements.
Hence, it takes a long time to boost yields using hybrids unless the government
forces farmers to use new seeds. China s rulers could do that; less
authoritarian regimes cannot.
Cereal killers
China s experience shows that a series of small improvements can add up to
something large. This will be true of the second revolution on the poorest
lands. The first green revolution had most impact on irrigated land and, thanks
to it, the 80m hectares which are irrigated (an area equivalent to Vietnam,
Laos and Cambodia put together) now have yields of five to six tonnes a
hectare; they produce three-quarters of the world s rice. But there is nearly
as much rice land which depends on rainwater. Yields there are far lower
between one and two and a half tonnes a hectare and rain-fed lands produce only
a quarter of the world s rice. Yields are low because almost half this land is
prone to drought and a third to floods. Most African paddies fall into this
category, which is why the first green revolution passed Africa by.
Drought- and flood-tolerant seeds could double yields from these areas. That
would boost harvests from 110m tonnes to 220m, and push global output to 550m
tonnes enough to meet expected demand in 2035. In short, all the extra rice
could come from rain-fed areas alone.
Because yields on rain-fed lands are low, even a doubling would not increase
total production by as much as the first green revolution did. But the impact
on poverty would be greater. More than 500m of the absolute poor (those with
$1.25 a day or less) depend on rice, far more than on any other food (see chart
2). A disproportionate number of them live in north-east India, Bangladesh and
the Irrawaddy delta of Myanmar. In these areas the lowest castes and tribes
have been forced onto the worst lands.
Those are the very places where the second green revolution would make the
biggest impact. Flood-resistant rice differentially benefits [India s]
scheduled castes and tribes , a recent study of one of the early field trials
concludes. If these improvements were combined with another programme to boost
the nutritional quality of rice the so-called Golden Rice project which
genetically modifies rice to include additional vitamin A then the benefits to
some of the poorest people in the world would be vast.
The first green revolution did not improve people s livelihoods just by
providing technological fixes. It did so because the new seeds attracted new
capital into farming, encouraged mechanisation, credit markets, new management
techniques and so on. The second revolution will also do this. Already, rice
farming is changing faster than for generations. Age-old habits of raising
seedlings, transplanting them into the fields and threshing, drying and storing
the plant are being rejected. Now, seeds are planted directly into the field by
machine and everything from threshing to milling is done by specialist firms.
For such changes to become more widespread, though, incentives and policies
need to push in the right direction. Alas, they don t all do so.
Seeding the next revolution
On the face of it, the second revolution is subsidised. Not only do governments
finance the basic research. In many Asian countries, from rice importers such
as Indonesia to exporters such as Thailand, they also pay farmers above the
world price. Thailand s scheme is so generous that it ran out of money this
year. Such price distortions artificially boost demand for green-revolution
seeds in the short run.
But high domestic prices are also bad for the economy. They impose heavy costs
on consumers. And they undermine incentives to export, making world prices more
volatile and international markets thinner. This hurts farmers who stand to
gain from the shift of comparative advantage in rice-growing towards India and
Bangladesh thanks to the second green revolution. If world trade becomes even
more marginal, any advantage those countries gain will be muted.
High domestic prices also tend to drive up local wages, reducing the
competitiveness of manufacturing and making rural labour dearer. And by making
rice farming a safe bet, the policies blunt entrepreneurship in agriculture
too, reducing farmers incentives to invest in new machinery and new ways of
farming. On balance, therefore, artificially high rice prices make the new
generation of seeds attractive, but by less than one might expect.
Land-use policy is equally messed up. In America and Europe technological
change has tended to make farms bigger. The bigger the operation, the greater
the gains from technology. That has not happened in Asia. In the most
productive irrigated areas, farms are often smaller than two hectares and,
despite mass migration from the countryside, have been getting even smaller
during the past three decades. Governments have intervened to prevent farm
consolidation partly because they want to slow down urbanisation, fearing that
it could drive up unemployment in cities. Such policies have only not done
considerable harm because of an extraordinary proliferation of efficient rental
markets (see article).
The original green revolution transformed Asia from a continent stalked by
hunger into one that could think and plan beyond the next harvest. It helped
lay the foundation for the continent s economic miracle and made possible Asia
s demographic transition from high fertility and high mortality to smaller,
richer families. The second green revolution will not do that. But it should
complete the first one, mainly by bringing benefits to the poorest, who missed
out first time round. It will help mechanise and move more people off farms and
into more productive labour. And it should prevent Asia slipping back under the
shadow of hunger and all the political and social disruptions that such misery
causes. Few other things can promise as much.