Nutrition and climate-resilience for cereal crops
Source: Flickr, ICRISAT
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Since the green revolution, India has experienced large production increases in high-yielding staple cereals (rice and wheat). However, the increasing predominance of these less nutritious staples (as compared to sorghum or pearl millet) poses significant malnutrition burdens, especially on low income subsistence-based farming households who rely predominantly on these cereals. In addition, there are significant concerns over the long-term sustainability of these crops.

A recent paper in Global Food Security examines trade-offs and synergies in terms of nutritional output, climatic resilience and price of four major crops (rice, maize, small millet and sorghum) grown in central India.

The study region encompasses 34 districts in central India spanning the states of Chhattisgarh, Madhya Pradesh and Maharashtra, covering 7.6 percent of the total land area of the country. The study uses data on the four monsoon cereal crops (maize, small millet, rice and sorghum) from the Government of India agricultural census; this data include yields per season from 2000 to 2012, area sown, and irrigated area for each district. The study also draws on data regarding nutritional content, temperature and rainfall data and prices from various sources. Based on this data, the study estimates the nutritional yields, the sensitivity of yields to monsoon rainfall and temperature, and average prices of each crop through a series of equations. Using the results from the equations, the study then assesses trade-offs and synergies among the four cereal crops, comparing average nutritional yields for all 34 districts for 2000–12, climate resilience and price.

The study highlights that between 2000 and 2012 rice was on average, sown on 70 percent of the total cereal area cultivated, sorghum on 12 percent, small millet on 9 percent and maize on 8 percent. Despite the predominance of rice, the study finds that it performs poorly in comparison to the other cereals grown in the region across several attributes. Regarding yields, the study finds that tonnes per hectare averaged 0.87, 1.09, 0.37, and 1.63 for rice, sorghum, small millet and maize respectively. The average purchaser's price in 2008 was Rs. 8600, 16,780, 8400, and 8400 per tonne for sorghum, rice, millets and maize respectively.

Combining nutritional yield per hectare the study finds that: rice has the lowest nutritional content for iron (fulfilling the dietary requirements of 2.6 adults per hectare), while maize has the highest protein content (fulfilling the dietary requirements of 9.1 adults per hectare) and small millet the lowest protein content (fulfilling the dietary requirements of 1.9 adults per hectare), sorghum has the highest iron content (fulfilling the dietary requirements of 12.4 adults per hectare). Regarding climatic resilience, the study finds sorghum is the most resilient to variability in precipitation, followed by small millet, maize and rice respectively. Susceptibility to temperature variation is only found to be a significant variable for sorghum but for the three other cereals temperature, variations are not found to be a significant variable.

Regarding synergies and trade-offs, the study discusses that each of the four monsoon cereals have different desirable attributes but that no cereal is superior in all attributes considered in the analysis. Sorghum provides the highest nutritional yield for iron while maize provides the highest nutritional yields for energy and protein. Sorghum is the least sensitive to variability in precipitation but most sensitive to temperature variability. Small millets are resilient to temperature and precipitation variability, but have low nutritional yields due to low overall yield. Generally, rice compares poorly to sorghum and maize regarding nutrition per hectare, climate resilience, and yield per hectare in the study area, and is least resilient to precipitation variability, has the lowest nutritional yields for iron, and the second lowest nutritional yields for energy.

The paper highlights that price incentives have generally been strong for rice in terms of purchaser's price, as well as minimum support prices.  The price supports coupled with extension services that promote rice are likely to be main drivers contributing to the predominance of rice in the study region and India in general despite the desirable characteristics of other cereals. Similarly, the paper discusses that a lack of milling technology, declining seed quality, and shortage of research devoted to increasing yields for other cereals have diminished their popularity.

In conclusion, the study highlights that the choice of crops, crop varieties, and crop combinations should be taken based upon the climatic context and nutritional needs of the population. For instance, iron deficiency is likely to be widespread in the study region and therefore an increase in sorghum consumption would use land efficiently to produce more iron per hectare. The study also suggests that in this study region where subsistence farmers generally rely heavily on cereals to provide nutrition, attention to expanding the production of nutritious cereals (such as sorghum and millets) could contribute to a more efficient use of land to improve nutritional outcomes. In addition, climate models are robustly predicting increasing variability in precipitation and increasing temperature across India, which will have significant negative effects on rice yields; a shift to the production of sorghum and millets can help mitigate the negative yield effects of changes in the climate.

The full study can be accessed here.

By: Bas Paris

Photo credit:Flickr, ICRISAT