Notes by Narsi

Intro

75-80% of freshwater is used for agriculture in India.

The Indian industry uses about 13% of freshwater, implying domestic/residential water consumption accounted for less than 10% of total freshwater use - something most of us will be surprised with.

/Intro

Section 1

India is not an exception

If you thought that it was a very high proportion used for agriculture, the scenario is similar in many countries worldwide. The global average is 70%.

/Section 1

Section 2

Some countries use even more

Some countries in Latin America & Africa use over 90% of freshwater for agriculture!

The proportion for USA is much smaller

% freshwater use in agriculture for some prominent  countries

• Germany 73%

• China 65%

• Japan 61%

• Australia 60%

• United States 42%

Makes one want to spend more time to figure out how the US has managed such a low percentage. Or is it that the residential or industrial segment uses far per capita than those for the rest of the world?) 

/Section 2

Section 3

Why does agriculture consume so much water?

It is partly because of inefficiencies in irrigation, but part of the reason also has to do with the fact that some of the most popular crops are water guzzlers. For instance, rice, soybeans, sugarcane, wheat and cotton, all crops that are produced in large quantities are crops requiring some of the highest amount of water for their growth. 

/Section 3

Section 4

Water consumption: Rice vs. millets: 2500 liters vs. 400 liters

A Kg of rice needs 2500 liters of water, while millets, which can be at least a partial rice substitute, needs only about 400 liters per Kg. But while India consumes 100 million tons of rice every year, its consumption of millets is far less - the country produces only 12 million tons of millets a year and the global production of millets is in itself only about 30 million tons per year.

/Section 4

Section 5

Water consumption: Cotton vs. hemp: 20,000 liters vs. 3,000 liters

A similar case exists for cotton vs. hemp. Cotton needs about 20,000 liters for a Kg. Hemp needs just about 3000 liters. Similar to millets, hemp can at least be a partial replacement or blend for cotton. While about 27 million tons of cotton fabrics are produced every year, the amount of hemp based fabrics are produced is an order of magnitude lower. 

/Section 5

Section 6

Water use efficiency: India vs. USA: 22,000 liters vs. 8000 liters

Even for crops that need large quantities of water, efficient irrigation can make do with less. For instance, while India uses about 22,000 liters of water to produce 1 Kg of cotton, the US uses just 8000 liters per Kg.

/Section 6

Section 7

Water use intensity in agriculture & industry

Taking India’s case, if agriculture uses 80% of water, how does its water use intensity (use as a proportion of the economic output) compare with that for industry?

The percentage contribution of agriculture to India’s GDP is about 20% while that for industry is about 80%.

Thus, agriculture consumes about 80% of water but produces only 20% of  GDP, while industry consumes just over 10% of water but contributes 80% to GDP. Water intensity as a proportion of economic value of output for agriculture is 32 times that for industry. 

While such a comparison does have its challenges - comparing agriculture and industry is  not an apples to apples comparison in this context - the dramatic difference in water intensity between industry and agriculture does make one reflect on it.

/Section 7

Section 8

What can be done to reduce agriculture’s use of water?

This is a wide topic for discussion, but the following seem to be the top 3 avenues based on my analysis:

• Use drip irrigation

• Use precision farming techniques - data and analytics for water use

• Optimal crop mix, or crop cultivation techniques, including drought tolerant crops, crop rotation, cover crops, mixed cropping etc..

/Section 8

Section 9

How can the UK use only 1% fresh waster for agriculture?

The stats for UK appear unbelievable

I read in many places that the UK uses only 1-2% of its total freshwater for agriculture. This appears unbelievable, especially given that the UK has a large and thriving agriculture sector.

No amount of research has gotten me to the bottom of this. Can anyone help? If indeed the above estimate is correct, shouldn’t the entire rest of the world fly all their agricultural experts to find out how they did it?

/Section 9