Improved Rice Cultivation

Food

Improved Rice Cultivation

Half the world eats rice. Flooded paddies are one of the largest sources of methane on Earth. The fix is to stop keeping them flooded, and it raises yields.

⚡Lightning

The effect is immediate. This stops an emission that is happening right now.

Project Drawdown classifies this as Emergency Brake.

Origins

Rice feeds more people than any other crop and has done for several thousand years. It is not going anywhere, and any climate argument that treats it as a problem to be eliminated has already lost half the planet.

The flooding was never about the rice. Rice does not need standing water; it tolerates it. The paddy was flooded because water suppresses weeds, and before herbicides that was the cheapest weed control available. A flooded field is a field a farmer does not have to weed by hand, and for a smallholder with a family to feed, that is not a small thing.

The unintended consequence took a long time to see. Waterlogged soil goes anaerobic, and in anaerobic soil a family of microbes called methanogens flourish, and what they produce is methane. A flooded paddy is, chemically, a shallow bog with a crop growing in it, and it exhales.

The alternative was worked out not in a laboratory but in Madagascar, in the 1980s, by a French Jesuit priest named Henri de Laulanié who had spent decades watching farmers. He noticed that rice planted younger, spaced wider, in soil kept moist rather than flooded, produced dramatically more grain. It became the System of Rice Intensification. It was greeted with considerable scepticism by agronomists, some of it deserved, and it has since been adopted by millions of farmers who found it worked on their own ground.

It remains one of the few climate solutions discovered by a priest watching peasants.

What it actually is

The mechanism is simple: let the field dry out, periodically.

Alternate wetting and drying — letting the paddy drain and the soil breathe before re-flooding — interrupts the anaerobic conditions the methanogens need. The methane production collapses. The rice, which never needed the standing water in the first place, is generally fine, and frequently better: roots grow deeper into aerated soil, plants tiller more, and yields commonly rise.

The System of Rice Intensification goes further and changes the whole method: transplant seedlings much younger, space them far wider, keep the soil moist rather than flooded, and weed mechanically. Fewer plants, more grain from each. It uses less seed and less water and, in a great many documented cases, produces substantially more rice.

The co-benefits are large and they are why farmers actually adopt it. Water, above all: rice consumes an enormous share of the world’s irrigation water, and alternate wetting and drying can cut water use by a quarter or more. In aquifer-depleted regions like the Punjab, that is not a climate argument. It is a survival argument.

And unlike almost everything else in agriculture, the emissions reduction is immediate. Stop flooding, and the methane stops. This is why it is a lightning solution.

The numbers

The methane. Rice cultivation is one of the largest single agricultural sources of methane, contributing on the order of 10% of global agricultural greenhouse gas emissions and a substantial share of human-caused methane. Methane is roughly 80 times more potent than CO₂ over twenty years, which is exactly why cutting it acts fast.

The water. Rice uses a very large share of global irrigation water. Alternate wetting and drying can reduce water use by around 25–30% with no yield penalty, and often a gain.

The yield. This is the part that makes it politically possible: improved rice methods frequently increase yields. SRI trials have reported gains that range from modest to spectacular, and while the most extreme claims have not always replicated, the direction of the effect is consistent enough that tens of millions of farmers have adopted it voluntarily — which is the only trial that finally matters.

The scale. Rice is grown on roughly 165 million hectares and feeds more than half of humanity. Small per-hectare improvements across a base that size are enormous.

The honest caveat. Drying the soil can increase nitrous oxide emissions, which is a far more potent and longer-lived gas. Done carelessly, you trade methane for something worse. Water management has to be managed, not merely reduced.

Why it matters

There is something quietly hopeful in the fact that the largest methane fix in agriculture is available to the poorest farmers on Earth, requires no technology they do not have, and pays them for doing it.

Most climate solutions ask somebody to give something up. This one asks a rice farmer in Bihar or the Mekong Delta to use less water, less seed, and less labour, and to harvest more grain. It is not a sacrifice she is being asked to make for the atmosphere. It is a better way to farm that happens, as a side effect, to stop a very potent gas from leaving her field.

Rice has fed Asia for five thousand years. The people who grow it are not a problem to be solved, and they have been treated as one often enough to be sceptical of anyone arriving with advice. What is being proposed here is not a break with their tradition. It is a refinement of it, worked out largely by farmers, spread largely between farmers, and adopted because it works in their own field, on their own soil, with their own eyes as the evidence.

That is how agricultural change has always actually happened. Not from a podium. Over a fence.

What it actually takes

Water control, which many farmers do not have. Alternate wetting and drying requires the ability to drain a field and re-flood it on demand. A farmer at the tail end of a canal system, taking water when it comes, cannot do this. The barrier is irrigation infrastructure and water governance, not willingness.

Weeds, the reason for the flooding in the first place. Drain the paddy and the weeds come. Mechanical weeding is labour, and labour is the scarcest thing a smallholder has. This is the real trade and it is why the practice spreads unevenly.

Not trading methane for nitrous oxide. Careless drying increases N₂O, which is far more potent and much longer-lived. The water management needs to be done properly, which means extension support, which is exactly what has been defunded across much of Asia.

Farmer-to-farmer, not top-down. Every attempt to impose rice methods from a ministry has gone badly. SRI spread because farmers saw a neighbour’s field and asked. That remains the mechanism, and programmes that respect it succeed.

Where it matters most

The Mekong Delta is the world’s rice bowl and its most acute crisis: sinking, salinating, upstream-dammed, and growing rice for a large share of Asia. Water-efficient rice is not optional there; it is existential.

The Gangetic plain and the Punjab are where rice is drinking an aquifer dry. Alternate wetting and drying is being adopted there for water reasons, and the methane reduction is a bonus nobody had to argue for.

The Yangtze Basin and the North China Plain are where the largest absolute reductions are available, simply because that is where the most rice is.

Indonesia, the Philippines and Madagascar — the last being where the method was worked out in the first place, and where the story began.

How to tell it’s being done well

Are they measuring nitrous oxide, not just methane? The trade is real. A programme reporting methane reductions with no N₂O measurement may be reporting a net loss and calling it a win.

Do the farmers actually control their water? Without drainage and re-flooding on demand, this cannot be done, and pretending otherwise sets farmers up to fail.

Did yields hold or improve? If a programme is asking farmers to accept lower yields for the atmosphere, it will not last a season and should not.

Is it spreading farmer-to-farmer? The programmes that work look like neighbours copying neighbours. The ones that fail look like a ministry with a target.

What you can do

Anyone

  • Rice is the crop that feeds the most people and the one least discussed in climate conversations in wealthy countries. That imbalance is worth correcting.
  • Support organizations working on smallholder water management. It is one of the highest-leverage and least glamorous fields in the entire climate effort.

Rice farmers

  • Alternate wetting and drying saves water and seed and usually does not cost yield. Try it on one field first.
  • Younger seedlings, wider spacing, moist rather than flooded soil. It contradicts everything most people were taught, and millions of farmers have found it works.
  • Watch a neighbour do it before you change your whole holding.

Policymakers

  • Fund irrigation infrastructure that gives farmers control over their own water. Without drainage, none of this is possible.
  • Rebuild agricultural extension. This is knowledge-intensive change and the knowledge has to travel.
  • Do not price water at zero. Rice is drinking aquifers dry partly because nobody is charged for the water.

Business and investors

  • Rice supply chains are enormous and almost entirely unexamined for methane. This is a large, cheap, unclaimed reduction sitting in plain view.
  • Fund water infrastructure at the smallholder scale. It is the binding constraint.

Who is working on this

We are researching which organizations in our directory of 8,493 actively work on this solution, and we only list an organization once we have verified it. That research is ongoing. In the meantime, search the directory yourself:

Search the directory for “Improved Rice Cultivation” →

Questions

Why do rice paddies emit methane?

Because standing water makes the soil anaerobic, and in oxygen-free soil a family of microbes called methanogens flourish and produce methane. A flooded paddy is chemically a shallow bog with a crop growing in it. Rice cultivation is one of the largest agricultural sources of methane on Earth.

Why are paddies flooded if rice does not need it?

For weed control. Rice tolerates standing water; it does not require it. The flooding suppresses weeds, and before herbicides that was the cheapest weed control available. For a smallholder without hired labour, a flooded field is a field she does not have to weed by hand, which is not a small consideration.

What is alternate wetting and drying?

Letting the paddy drain and the soil breathe periodically before re-flooding. It interrupts the anaerobic conditions the methane-producing microbes need, and methane production collapses. It typically cuts water use by around a quarter with no yield penalty, and often a yield gain.

What is the System of Rice Intensification?

A method developed in Madagascar in the 1980s: transplant seedlings much younger, space them far wider, keep soil moist rather than flooded, and weed mechanically. Fewer plants, more grain from each. It uses less seed and less water and in many documented cases produces substantially more rice. It has been adopted by millions of farmers.

Is there a catch?

Yes, and it is important. Drying the soil can increase nitrous oxide emissions, which is far more potent and much longer-lived than methane. Done carelessly, you trade methane for something worse. The water management has to be genuinely managed, not merely reduced, which requires extension support.

Why is this classed as a fast-acting solution?

Because the methane stops almost immediately when the flooding stops. There is no decades-long accumulation to wait for. Methane is also roughly 80 times more potent than CO2 over a twenty-year horizon, so reducing it produces a rapid atmospheric response.

Sources

The solution taxonomy follows the framework popularised by Project Drawdown. The analysis above is our own; for their carbon modeling and rankings, visit them directly.