How can we get more crop per drop?

A recent study by the International Food Policy Research Institute (IFPRI) and International Water Management Institute (IWMI) projects that if present trends continue, by 2025 competition from growing cities and industry worldwide will limit the amount of water available for irrigation, causing annual global losses of 350 million metric tons of food production. The environment will also sustain further damage, as water from this already thirsty sector is diverted to agriculture, households and industry. And if levels of investment in sustainable water policy and management decrease over the next 20 years, the result will be major declines in food production, thereby skyrocketing food prices.

By improving the productivity of water used for agriculture by 40 percent, it's possible to reduce the amount of additional freshwater withdrawals needed to feed the world's growing population to 0. Research done over the past decade shows that by improving the productivity of water on irrigated and rain-fed lands, we can have enough water for cities, industry and nature. But this requires a commitment to institutional and management reforms, and substantial investment in crop research, capacity building, technology and infrastructure.

Agriculture is the mainstay of the economy of Bangladesh though in recent years, emphasis has been given on industrialisation to accelerate economic growth. Crop production is the largest activity within the agricultural sector, which accounts for about 62 percent of the country's total labour force.

Three major rivers of the world, the Ganges, the Brahmaputra and the Meghna, having a combined catchment area of 1.72 million sq. km. flow to the Bay of Bengal through Bangladesh, a land that constitutes only about 7 percent of the catchment area of these rivers. These along with other cross-border rivers bring about 1060 billion cubic metre (BCM)of water into the country. However, the dry season flow (November to April) from these cross-border rivers amounts to only 159 BCM. In the critical dry month of March when the water demand is at its peak, the river flows reduce to a mere total of 18 BCM, which is far below the total demand.

On top of all, due to building dams and barrages unilaterally in the major transboundery rivers in the upstream by neighbouring India, the whole northern region of Bangladesh, the lowest riparian of these rivers, is being desertified. Conversely, siltation of river beds caused by huge sediments carried by rivers from upstream countries decelerates drainage and accentuates the intensity of floods. Moreover, lack of governance coupled with ineffiency and rampant corruption in our public life has been aggravating the situation.

There's a further complication that as the country is mostly flat the storage possibility in the country is virtually non-existent. Joining in these, rivers aren't dredged properly. Furthermore, ingress of salinity due to reduced upland flows during the dry season affects about two million hectares of land in the southern belt of the country. And groundwater recharge is about 22 BCM annually. But, the incidence of arsenic contamination of groundwater now calls for very restricted use of this resource. Also, rainfall in the dry season is very erratic and negligible.

The highest demand for consumptive (withdrawal) use of water is from the agricultural sector while huge amount of water is needed in-stream too for navigation, fish and above all, environmental protection. Present demand for potable supply and industrial use is smaller relatively.

Improving the productivity of water used in agriculture is the key to solving many of the problems, as well as managing water as a resource. Getting more crop per drop enhances food security and makes more water available for nature, industry and domestic users. It enables us to reduce the need for investments in new water storage and irrigation infrastructure -- investments many countries like Bangladesh can't afford. By improving the productivity of water on rain-fed lands, we can contribute to the food security and incomes of the poorest people.

Many people associate water saving with municipal water use -- encouraging domestic users to practise water conservation and cities to plug up leaking supply systems. While these efforts have localised benefits, it's important to realise that cities actually consume very little of the world's water. Even in developed countries where most households have easy access to municipal water supplies, a person uses less than 150 litres of water a day. Compare this to the 2,000 to 5,000 litres of water required to produce enough food to feed one person one day and you begin to understand why finding ways of getting more crop per drop is vital to not only the country's future but also the world's future.

Improving productivity
What actions are needed? There are a variety of interconnected paths that can improve the productivity of water. No single path holds the answer. To be successful we must develop integrated strategies tailored to the needs of our country, the region and river basins.

Crop breeding: Crop breeding over the last century has indirectly increased the productivity of water by increasing yields without increasing crop water demand. It's only in the decade that attention has turned to producing crops that can yield more with less water, withstand water scarce conditions, and thrive on low-quality (saline/alkaline) water. Scientists have already identified traits and genes for drought- and salt-tolerance in a number of crops.

Reducing land degradation: Land and water degradation constrain efforts to improve water productivity. Soil erosion, for example, reduces not only soil's depth but also its capacity to hold water and the amount of nutrients it contains. There is a common misperception that degradation of the agro-ecosystems is a slow process that can be always reversed with adequate inputs such as fertilizer. But ecosystems are resilient only up to a certain threshold, and can collapse when pushed too far. In many cases, farmers need incentives to make long-term investments in soil conservation practices -- particularly when results from such investments do not have a direct or significant impact on their incomes. Social and institutional factors, such as land tenure, also affect farmers' willingness to invest.

Low-cost technologies: Various forms of precision irrigation -- mainly sprinkler, drip irrigation systems and dead-level basins -- can increase yields over good but ordinary irrigation systems by 20 to 70 per cent, depending on the crop and other conditions, and they do so with much less water diverted to the crop.

Improved irrigation management practices: Perhaps the most important basic principle in irrigation is to deliver a reliable supply of water. In an uncertain environment, farmers will not invest in seeds, fertilizers, and land preparation, and consequently yields and water productivity will suffer.

A second basic principle has to do with timing. At various times in a crop's growth cycle, water stress can be particularly damaging.

Groundwater arsenic poisoning has gripped almost all the 64 districts of Bangladesh. That's why the nation is desperately looking for an alternative source of water. And there's no other source of water but surface water. Unfortunately, the country's surface water almost everywhere is extremely polluted by free-flowing toxic industrial effluents. The industrialists here are highly influential in society, by virtue of having links with corrupt ruling high-ups. So, nobody dares speak against them, let alone the poor farmers. And here's our major national crisis, which is holding back continuously all our growth.

Integrating recycling and reuse into basin and irrigation management : Water reuse is already becoming an integral part of water management in many water-scarce areas. For example, it's common practice for farmers in Egypt and North China to place small pumps in drainage ditches to reuse water. The irrigation agency supports this reuse strategy by blending drainage water with freshwater to increase the useable supplies.

Many farmers in peri-urban settings rely on wastewater from cities for their crops. Irrigating with low quality water is often the only option; but even when farmers do have access to canal irrigation, many prefer wastewater because they're guaranteed a constant supply, and the nutrients the water contains allow them to save on fertilizer. Pollution and health risks should be considered when crafting reuse strategies. In Bangladesh, wastewater from cities and towns is "openly and freely" mixed with toxic industrial effluents not caring a damn about environmental and health hazards and laws, most often under the patronage of ruling bigwigs.

Where more research needed

• Crop breeding for drought tolerance, water conservation, and ability to thrive on low-quality water.
• Understanding the interaction between water management practices at different levels -- field, system, basin.
• Co-managing water for agriculture and the environment.
• Appropriate pro-poor technologies and practices for improving water productivity at field and system levels.
• Policies and incentives needed to implement water-saving technologies and practices.
• How to manage irrigation water for multiple uses -- crops, domestic, other income-generating activities.
• Tools and models to support responsible decision making for valuing the productivity of water in its various uses.

Policy, institutions and incentives
For any of these strategies to work requires the right set of incentives and support for all the actors involved -- a function of policies and institutions. And capacity building along with social participation is a crucial factor for effective management of water and river basins. Existing institutions for water management must be more efficient and sincere in offering services that will support improvements in water productivity. The country's poor farmers need incentives and subsidies to adopt technologies and practices to make the most of the water they use.

As competition for water is becoming more intense, how water is managed in one sector often impacts its availability in others. Laws, regulations and organisations should be well defined to encourage water management from a basin perspective.

Another area which should be targeted for reform is subsidies and pricing. In many cases, poorly designed subsidies coupled with corrupt system can actually discourage farmers from getting the most crop per drop.

Increases in water productivity are necessary to solve many of the problems of the water crisis, but they're not sufficient. It's imperative that these be accompanied by a poverty focus to help the poor reap the gains of increases in water productivity. Attention needs to be given to establishing and maintaining access to water for domestic uses and income generation, and affordable water-productivity-enhancing technologies, and giving the poor a voice in water decisions.

Whose responsibility is it? Increasing water productivity requires the coordinated set of actions from a range of people: policy makers, recourse managers, farmers, fishermen, and water managers; researchers from agronomy, water resources, irrigation, and natural resources management; and in fact all of us who care about influencing policies about how water is used. Finally, a good regional cooperation is essential for sustainable water management from a basin perspective.

Md Saiful Haque is a freelance journalist and member, International Federation of Environmental Journalists (IFEJ). He attended World Water Week in Stockholm, recently.