The warming of the earth’s climate system since the last five decades has brought in ominous changes all over the world. Extreme weather events (cold and heat waves, floods and droughts) are becoming frequent occurrences globally, and cold days and nights are reducing against the increasing number of warm days and nights (IPCC, 2014). Such conditions affect plant systems and their life cycles, crop growth and development, thereby reducing the quality or quantity of crop plants (Tripathi et al., 2016). Studies have indicated that a 1oC increase in global temperature will lead to reduced productivity in cultivated plants (Lobell et al., 2013). Though there are some positive impacts of increasing carbon dioxide concentration in carbon fixation process in plants, the resultant increase in temperature negate this and affect the production and quality of many crops especially the traditional or climate-adapted food crops (Ludwig & Asseng, 2010; Tripathi & Singh, 2013).
Traditional crops and their importance
Traditional crops are the indigenous varieties developed over decades or centuries to ensure good, sustainable yields in a specific region. These have immense importance in crop rotation, inter-cropping, mixed cropping and in adaptation to harsh environmental conditions. In many other developing countries with rich agricultural traditions, the changing climate and related weather shifts are taking their toll on ‘traditional crops’, resulting in an alarming loss in agro-diversity.
Between 1966 and 2006, 44 per cent of traditional crop cultivation areas were occupied by other crops signifying an extraordinary loss to India’s indigenous food and farming systems (NIRMAN, 2014). This can be partly attributed to the then widespread belief that traditional agriculture was incapable of meeting India’s desired agricultural objectives.
Climate change portends less rain, more heat, less water and increased malnutrition. If there is any cropping system that can withstand these challenges, survive and flourish, it is the traditional cropping system. The traditional crops that have gone into disuse are not the mainstream crops, but the ones used for mixed cropping and inter cropping in the areas where other crops fail due to irrigation stress and low soil fertility. As changes in temperature and related weather shift became prevalent some of these crops became less responsive. People started following the wheat and rice pattern and grew hybrid varieties and thus traditional crops progressively failed to adapt to the current weather extremes.
However, the current hybrid wheat-rice cropping system is no longer sustainable and with the projected 2ºC temperature rise, wheat might disappear since it is an extremely thermal sensitive crop. Similarly, extreme uncertainty in rainfall and triggered droughts in our country is making it hard to get good yields in rice.
However, there are traditional crops which are climate change compliant and can be cultivated round the year. These crops ensure food, fodder, health, nutrition, rural livelihood and ecological security. These varieties give high yields, aroma, and have better cooking qualities.
Some are drought tolerant (Setaria italica, Crotalaria sp., Sesamum indicum), some are low temperature tolerant (Paspalum scrobiculatum, Linum usitatissimum) while some are flood-tolerant (Euryale ferox). Some important traditional crop varieties and their climate resilient features are given in Table 1. Many of them thrive well in disturbed soils (Pennisetum typhoides), hot climate and can survive severe water-deficit and osmotic stress. Some of these crops have special characteristics to withstand strong winds and desiccation as well. Apart from their climatic adaptability, they are also beneficial for crop rotation, inter-cropping, double cropping and mixed cropping that not only maintain the fertility of the soil but help in ecological integrity and biogeochemical cycling. These crops generally have low saturated fat, no cholesterol, very low sodium, low sugars, and high manganese, making them extremely beneficial for human health.
Impact of climate change on traditional crops
However, experts have found that extreme changes in temperature, light intensity, photoperiod, and relative humidity have affected the agronomic traits of traditional crops too (Yang et al., 2013). Gradual reduction in yield coupled with irregularities in weather patterns over the years has seen many traditional crops replaced by high yielding crops. This was in spite of our traditional crops being better suited for extreme climatic conditions. Lack of organised production and supply of improved seed varieties, changing food habits, time consuming and cumbersome procedures of food preparations of almost all traditional crops are some factors.
Shifts in crop sowing and harvesting timings owing to changes in climatic conditions have greatly affected crops (Tripathi & Singh, 2013). Other impacts on crops concern stomatal responses, photosynthetic processes, transpiration, and nutrients like protein, lipids, non-structural carbohydrates, and minerals, resulting in changes in crop quality (Tripathi et al., 2015). Climate change also affects the respiration coefficient and dry weight maintenance coefficient of these crops, which incidentally are important qualities to sustain in harsh environments (Baligar et al., 2012).
In some wild rice varieties, high temperature affects gelatinisation temperature and amylase content which either decrease hardness in grains or increase stickiness (Hoover et al., 1996). Shorter starch accrual and loss of fermentable sugars may occur in wild barley granules (Hordeum spontaneum) at high temperatures (Savin & Nicolas, 1996). Increased temperatures reduce the amounts of non-polar lipids which influence milling and baking properties of many traditional crops (Kumar & Parikh, 2011).
For traditional millets, the above-ground organs of the plants such as leaves, stems, tillers, flowers and grains are affected by high temperature. Various reproductive changes also occur such as spikelet production, floral abnormalities, delayed flowering, and reduced pollen germination. These are dangerous for many traditional crop varieties (Cross et al., 2003). Some traditional rice varieties are on the verge of extinction from the Indo-Gangetic plain as they show crop failures associated with steep decline in yield (Echinochloa frumentacea) while kodo millet (Paspalum scrobiculatum) and maize (Zea mays) have shown some sustenance with decreased but sustained yields in the last 5-10 years (Tripathi & Singh, 2013).
Evidently, summer has increased in duration while winters have reduced, with a steep decline in rainfall over the plains of India (Tripathi & Singh, 2013). This has resulted in uncertainties and irregularities in the climate responses of several crops. This has both directly and indirectly affected the traditional cropping system in the country, with several traditional crops in various agro-regions hovering on the verge of extinction.
Agricultural policies have not been formulated to support or conquer declining agricultural production of these age old crops. In fact, the green revolution had only been focussed on rice and wheat. Plans have not been executed to overcome the inability of traditional crops to compete with the more remunerative crops, despite the fact that these have been the major source of rural livelihoods in India. Unless proper planning and attention is given to our traditional varieties, this trend could lead to the extinction of our traditional nutrient rich agro-biodiversity.
Stemming the Loss
Lack of state support through crop loans and crop insurance has significantly contributed to the decline and disappearance of traditional crop varieties in Indian agriculture. Plans ought to be made to use these crops in areas that they can thrive along with suitable governmental support to farmers. At a time when India is reeling under drought and adverse climate conditions, these varieties for mixed cropping, rotational cropping and double cropping may help bring climate resilience and improve soil fertility as well through better nitrogen assimilation and interrupted weed cycle. This can help in building a climate adaptive agricultural system that will particularly help marginal and poor farmers.
‘Climate insurance’ can especially prove a very good initiative in this regard. Unless urgent steps are initiated to check this situation through strong policy and financial incentives, these varieties might just disappear from our agrarian landscape over the next 50 years, leaving our food and farming systems poorer in the bargain. This can pave the way to major civilisational and ecological disaster.
Convoluted thinking on the part of planners at the governmental level saw the promotion of rice, wheat and several modern crop varieties while traditional crops were neglected. Today, when climate change threatens us with frequent droughts and other extreme weather events, it is high time that we fall back on climate-resilient traditional crops which can withstand water-scarcity and severe stress to survive, and give stable yields.
Baligar, V.C., Bunce, J.A., Elson, M.K., & Fageria, N.K. (2012). Photosynthetic photon flux density, carbon dioxide concentration and temperature influence photosynthesis in Crotalaria species. The Open Plant Science Journal, 6, pp1-7.
Cross, R.H., McKay, S.A.B., G Mchughen, A., & Bonham Smith, P.C. (2003). Heat stress effects on reproduction and seed set in Linum usitatissimum L.(flax). Plant, Cell & Environment, 26(7), pp1013-1020.
Garcia-Huidobro, J., Monteith, J.L., & Squire, G.R. (1982). Time, temperature and germination of pearl millet (Pennisetum typhoides S. & H.) I. Constant temperature. Journal of Experimental Botany, 33(2), pp288-296.
Hoover, R., Sailaja, Y., & Sosulski, F.W. (1996). Characterization of starches from wild and long grain brown rice. Food Research International, 29(2), pp99-107.
Horbowicz, M., Brenac, P., & Obendorf, R.L. (1998). Fagopyritol B1, O-alpha-D-galactopyranosyl-(1–>2)-D-chiro-inositol, a galactosyl cyclitol in maturing buckwheat seeds associated with desiccation tolerance. Planta, 205(1), pp1-11.
IPCC. (2014). Summary for policymakers. in: climate change 2013: the physical science basis. Retrieved from www.ipcc.ch/report/ar5/wg1/
Kumar, K. K., & Parikh, J. (2001). Indian agriculture and climate sensitivity. Global Environmental Change, 11(2), pp147-154.
Lobell, D.B., Hammer, G.L., McLean, G., Messina, C., Roberts M.J., Schlenker, W. (2013). The critical role of extreme heat for maize production in the United States. Nature Climate Change, 3, pp497–501.
Ludwig, F., Asseng, S., (2010). Potential beneﬁts of early vigor and changes in phenology in wheat to adapt to warmer and drier climates. Agricutural Systems, 103,(2010), pp127–136.
NIRMAN. (2014). NIRMAN Annual Report 2013-14. Retrieved from http://nirmanodisha.org/AnnualReports/Annual_Report_2013-2014.pdf
Savin, R., & Nicolas, M.E. (1996). Effects of short periods of drought and high temperature on grain growth and starch accumulation of two malting barley cultivars. Functional Plant Biology, 23(2), pp201-210.