- According to a study if Indian farmers were to switch from growing rice and wheat to ‘alternative cereals,’ such as maize, sorghum, and millet, it could reduce the demand for irrigation water by 33%.
Background: Importance of the study
- Global crop production has more than tripled since the 1960s, leading to increased food supply per capita, lower food prices and reduced malnutrition worldwide.
- However this has been accompanied by the depletion of freshwater resources for irrigation, nutrient pollution from injudicious fertilizer application and rising greenhouse gas emissions.
- There is therefore widespread agreement that agriculture’s use of planetary systems is unsustainable.
- We will need to feed an additional 2 billion people by 2050.
- This should also minimize the environmental consequences of the global food system.
- The need for improved compatibility between food security and environmental stewardship is of considerable urgency in India.
- India has remained largely self-sufficient in terms of cereal production over the past 50 years, with rice (grown during the kharif/monsoon season) and wheat.
- While the boom in rice-wheat systems has vitally contributed to reducing hunger and malnutrition throughout India, these trends in production have been supported by ever-increasing agricultural inputs and extensive environmental consequences, particularly for freshwater resources.
- Many parts of the country now experience chronic water stress due to heavy-water extraction for irrigated agriculture and a weakening monsoon , while widespread nutrient deficiencies persist.
- Because Indian diets generally derive a large fraction of nutrients from cereals, these mounting food security and environmental challenges make it increasingly clear that the rice-wheat status quo of the Indian food system requires critical examination.
- The historical growth in wheat production during the rabi (non-monsoon) season has been the main driver of the country’s increased consumptive irrigation water demand.
- Also rice is the least water-efficient cereal for the production of key nutrients, especially for iron, zinc, and fiber.
How was the study done?
- For their analysis, the scientists considered water as well as cereal-production data from 1996-2009.
- The researchers used Crop Water Requirement (CWR), which is the product of the water required by a crop and the harvested area — to calculate water consumption in every district in this period.
- Though cereal production grew by 230%, the combined production of alternative cereals had steadily reduced compared to that of rice and wheat in the said period.
- However, alternative cereals disproportionately account for the supply of protein, iron, and zinc among kharif crops.
- At the same time, total Crop Water Requirement demand for Indian cereal production increased from 482 to 632 km3 per year during the study period.
- This increase has been driven almost entirely by a doubling of consumptive blue water demand (refers to water extracted from irrigation) for wheat during the rabi season and modest increases in cropping frequencies and cropland extent.
- The largest increases in consumptive water demand occurred in Punjab and Haryana.
- It was found that rice is the least water-efficient cereal when it came to producing nutrients, and was the main driver in increasing irrigation stresses.
Time series of consumptive water demand for Indian cereal production
Key results of the study
- By replacing rice areas in each district with the alternative cereal with the lowest irrigation (blue) water footprint it is possible to reduce irrigation water demand by 33%.
- It also improves iron (+27%), and zinc (+13%)
- In some districts, however, the shift in cereals translated into a reduction in calorie content.
- Nutritional benefits: Replacing rice with maize, finger millet, pearl millet, or sorghum could save irrigation and improving production of nutrients such as iron by 27%, zinc by 13% and protein by 1%.
- The alternate cereals include maize, finger millet, pearl millet, or sorghum)
- It should be noted that the government procures rice and wheat to meet obligations under the Food Security Act.
- Adding alternative cereal production under Food security act can help distribute nutrient production across the country and reduce the impact of a single local climate shock to national grain production.