Can agroforestry save India's rivers and the farms that depend on them?

The very origins of Indian civilization can be found on the banks of rivers such as the Sindhu, the Sutlej, and the long-lost Saraswati. In southern India, human societies flourished near the Krishna, Cauvery and Godavari rivers. But today, these cradles of life are under threat.

Although there has been no significant dip in the volume of rainfall in the subcontinent, most of India’s rivers have depleted drastically over the past 70 years. Krishna has depleted by more than 60%, Narmada by 58%, Ganga by more than 40%, while the Cauvery River is 39% of what it was 50 years ago.

Only 4% of India's river waters are glacier-fed. The rest are mostly forest-fed and dependent on rainfall. In a tropical country like India, rivers, ponds, lakes and wells are all destinations for water, not sources. There is only one source of water: the monsoon rain. In India, precipitation predominantly occurs within two or three months of the year. The rainwater that falls in this short period has to be stored in the land for 365 days. If there is substantial vegetation, it will arrest the water, allow it to sink into the soil and release it into the rivers over the next 12 months. Otherwise, water will flow away and cause a flood.

Since independence, India has lost a large percentage of its natural forest - because of which, I would say, less than 20% of rainfall is being held in the soil.

When I was younger, I rafted down Cauvery on four truck tubes and twelve sticks of bamboo for 163km over a period of 12-13 days. What I saw was that except for the first 30-35km, there is no vegetation anywhere along its banks.

The situation is even worse today. I was at the Krishna Raja Sagara dam on Cauvery near Mysuru recently. A couple of decades ago, the dam's reservoir would take around 25 days to fill up after heavy rains. Today, it is filling up in four days because the water, instead of percolating into the soil and flowing into the river, is flowing swiftly across the ground and washing away soil. For the first time, the water flowing through the dam is brown because it is carrying a significant amount of sediment.

There is a very beautiful saying about Cauvery in the Tamil language: “Only if Cauvery comes walking, she is prosperity. If she comes running, she is a disaster.” Today, people are putting it like this: “Slow the flow.”

You can make rivers walk only if there is substantial vegetation in their catchment area. Insufficient vegetation, especially in a tropical climate, has wreaked havoc upon our rivers and led to desertification, turning soil into sand.

India has a long history of farming over thousands of years. But now, 60% of India’s 160 million hectares of arable land is considered 'distressed soil'. This means that in 30 years’ time, nearly 60% of India's arable land will become uncultivable.

Faced with dying soil and no water, more than three-hundred-thousand farmers across the country have committed suicide in the past 20 years. We have conducted a few informal surveys and found that less than 5% of the farmers in Tamil Nadu, a state in Cauvery basin, want their children to go into farming. We are losing the quality of the soil, as well as the next generation of farmers. If we do not make agriculture a lucrative process once more, we will lose our ability to grow food in this country within the next 25 years. With India’s population expected to be more than 1.5 billion by 2050, we are definitely heading for a major food crisis.

We need to bring more land under tree cover, but increasing forest cover is impossible in India due to population pressure. Since agriculture occupies more than 50% of the land, it is only farmers who can really increase green cover. The only way forward, therefore, is agroforestry or tree-based agriculture.

Over the past 18 years, we have been conducting small-scale agroforestry demonstrations in Tamil Nadu, and have brought 69,760 farmers into agroforestry. We have found that their incomes have gone up by 300-800% in five to seven years through the sale of timber and profitable intercropping. India imports INR630 billion ($8.9 billion) worth of raw timber and INR1.12 trillion ($16 billion) worth of timber products annually. Why shouldn’t Indian farmers produce and sell timber, and benefit?

We launched the Cauvery Calling initiative to revitalize Cauvery River by shifting farmers to agroforestry and supporting them to plant 2.42 billion trees in the Cauvery basin over the next 12 years. This will augment an additional 9-12 trillion litres of water in the Cauvery basin, which is 40-60% of the 21 trillion litres flowing every year in Cauvery right now.

Cauvery’s revitalization is a model for the entire tropical world because it is beneficial to all the parties involved – farmers, government and the people. Essentially, this is an economic plan with a significant ecological impact. The farmers' incomes will go up substantially. For the government, we have calculated that taxes from timber sale can bring in INR290 billion ($4 billion) by the twelfth year in just the state of Tamil Nadu alone. The other major state in Cauvery basin – Karnataka – could earn much more. And the people will live in a lush land, have more nutritious food, and be freed from water crises.