Water Management in Agriculture

ChackoThomas

Of all the factors that can make or mar a farmer’s crop and his consequent earnings, there is one factor that I think outweighs all other parameters: water. The lack, excess or even the quality of water has undoubtedly far reaching consequences for any crop, the economics and well-being of a nation especially India, where agriculture contributes higher than average to the nation’s GDP.

It is widely believed that while India accounts for about 17% of the world’s population it has only 4% of the world’s fresh water resources. Surveys conducted by the Tata Institute of Social Sciences (TISS) revealed that most urban cities are water deficient. Nearly 40% of water demand in urban India is met by ground water. As a result, ground water tables in most cities are falling at an alarming rate of 2-3 meters per year.  It is no surprise that even during peak monsoons in cities like Bangalore, water tankers are seen supplying water to housing societies.

If we consider agriculture and specifically rural India, the usage of water is by irrigation infrastructure which includes a network of canals from rivers, ground water, wells-based systems, tanks and other rainwater harvesting solutions. However, while globally, about 40% of irrigation water is supplied from ground water, in India it is expected to be over 50% (160 million ha of cultivated land) making it the most exploited natural resource, and what’s more alarming is that it’s mostly unscientific.  It is not surprising therefore that during the 2011 census, India entered the league of water deficient nations.

While many innovative solutions have been put forward by experts to tackle water scarcity, including efficient methods such as drip irrigation, weather and temperature-based controlled irrigation, rainwater & runoff water harvesting, water-based gel capsules and several others, I wanted to specifically call out recycling of wastewater for use in agriculture. Just recently I read an interesting article about water deficient Israel, living under extreme climatic conditions and their journey to water sufficiency.  While there is a lot of merit in the fact that Israel’s giant desalination plants have brought about a reversal, however, I understand that that is only part of the story. Very early on, Israel realized that water withdrawals for its farmlands were unusually high. The water level at its largest freshwater lake, the Sea of Galilee, was just inches above the danger mark. If it fell below that mark, irreversible salt infiltration of the lake would ruin the fresh water source for ever.

Israel imposed a year of unpopular but necessary water rationing and most farmers living in that fertile belt lost a year of crop. This had its political ramifications but a massive awareness campaign across Israel was conducted to explain to people how the water crisis was affecting the nation and how it was to be tackled. During that year, Israel started using recycled, slightly brackish water for irrigation. Today, 80% of Israel’s wastewater is recycled for agricultural use. The brackish water has lower treatment costs. It is good for agriculture but not good for human consumption without further treatment. Importantly, it gets wastewater recycled for consumption in the farms, and the sludge does not contaminate the fresh water sources.

This is a huge learning for us on how to reduce the water crisis in India – we need to change both, our recycling as well as supply mode.

75% of water pollution from domestic wastewater today, is discharged untreated into local water bodies and rivers. This amounts to around 40,000 MLD (million litres per day) from its 300 odd cities. Irrigation with wastewater may cost less because of lower purification levels.

We are blessed with rivers and the classic example is the Ganges which for many years has been a source of sustenance for both, the agriculturists as well as the several millions of people who live on the banks of this river. The initiative of the Prime Minister to clean the river has long been seen many as beyond the realms of the possible. However we do not realize that this initiative will solve two major issues: cleaning our national river as well as creating adequate water resources for use for agriculture. It is thus imperative that not just resources but adequate funding is allocated to this ambitious project.

However, I am told that India still does not possess the cutting-edge technology for treatment plants for such use or is just not willing to invest large sums of money into acquiring one. After all what can explain the tardy progress of the clean Ganga mission.  For a scientific and financial powerhouse like India can this be so difficult I wonder?! As for me, I cannot help but marvel at the thought that all our great rivers will be systematically cleaned and all the treated water will become eminently suitable for agriculture use by supplying treated wastewater to farmlands. We can go back from being a green country that is water deficient to a truly green country that is water surplus.

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