This research paper makes robust and systematic efforts to quantify the plausible future climate change impacts on post-rainy sorghum performance using both crop simulation and multi-model climate scenarios across the studied states in India. The findings in this paper will help scientists, agronomists, and policymakers in designing suitable climate adaptation strategies and policies for crop improvement.
Sorghum is an important nutraceutical crop for the small and marginal farmers across the semi-arid tropics (SAT) of the world. Globally, sorghum is the fifth largest cereal preferred in diverse ecologies. Primarily, the crop is cultivated in four (Asia, Africa, the Pacific, and the Americas) major regions across the globe. In India, sorghum is the fourth largest cereal crop. In the case of Africa, it is the second most important crop after maize.
Sorghum is one of the most preferred climate-smart crops for rainfed farmers under severe moisture stress environments. It can be grown successfully under limited soil moisture availability and with the inadequate application of other input. At present, the crop is being cultivated in both the monsoon (1.85 m ha) and post-rainy (2.89 m ha) seasons.
Nearly 1.5 m ha of cropped area is also under use for forage sorghum, which is cultivated during the summer season. More than 90% of the sorghum-cropped area in the country is grown under rainfed conditions. Rainy season sorghum is cultivated under both sole (40%) and intercrop (along with pulses and oilseeds) (60%) cropping systems. However, the post-rainy sorghum is preferred to cultivate as a sole crop under residual soil moisture conditions.
Sorghum is cultivated for diverse uses, such as food and feed purposes. The forage of the crop is highly nutritious for livestock animals. The crop also has a significant capacity for ethanol production and has been identified as a potential biofuel crop. Sorghum grains are the richest sources of Fe and Zn minerals, apart from starch and protein.
Since the late 1990s, there has been a remarkable shift in the sorghum-cropped area from the monsoon to the post-rainy season. The area proportions between monsoon (62%) and post-rainy seasons (38%) in the total sorghum-cropped area during the 1960s have been altered to 39% (monsoon) and 61% (post-rainy) by 2020–2021. The rain that occurs during the rainy season exactly coincides with the time of the rainy season sorghum harvest, resulting in poor quality for the grains due to grain mold attacks and fetching lower market prices.
In spite of significant crop improvement exertions by both the public and private sectors, the rainy season cropped area has been eroded in the country due to low profitability in its cultivation. The majority of the rainy season’s produce is diverted for industrial usage (mainly poultry) rather than human consumption.
Relatively, the average productivity levels are higher for the monsoon season sorghum because of good access to modern cultivars, including hybrids. The mean productivity levels are lower in the case of the post-rainy crops due to the non-availability of improved cultivars and moisture stress conditions. However, the quality of the grain is superior in the post-rainy season compared with that of the monsoon season.
Grain molds and shoot fly attacks during the rainy season often deteriorate the quality of monsoon production. A major chunk of the post-rainy season produce is diverted for human consumption and fetches higher market prices (nearly double) than rainy season grain. In both seasons, stover (straw) forms an important source of crop income as well as animal feed for their livestock. The leading states for growing post-rainy season sorghum in India are Maharashtra, Karnataka, Andhra Pradesh, Gujarat, and Telangana.
It is an important source of food, fodder, and livelihood for the sorghum growers in the niche areas located in these states. Historically, sorghum is a climate-resilient crop that developed its drought tolerance traits to withstand and respond to adverse climate conditions. It is a perfect crop for the SATs, which is a permanent home for the poorest of the poor people. Sorghum can thrive well under excessive temperatures, salt, and waterlogging situations. It is well-established that sorghum is a good potential crop for promoting household incomes as well as lifting the poor out of poverty.
Under the perils of climate change and variability (CCV), the plausible impacts on crop productivity levels across the world, especially in the tropics, are going to be very high. Increasing temperatures coupled with significant deviations in the annual rainfall distribution may exacerbate substantial negative effects in SAT regions. Post-rainy sorghum is likely to reduce its productivity per ha up to 7% by 2020, up to 11% by 2050, and up to 32% by 2080 due to anticipated climate change projections. The probable impacts will be severe and may vary their intensity across the post-rainy sorghum-cultivating agro-ecologies of India.
The introduction of climate-smart cultivars and an improved package of practices may compensate for the plausible impacts partially. However, significant crop productivity loss was noticed after a 2 ◦C rise in temperature and even after providing twice the quantity of rainfall across the major cultivating regions in India. With this background, it is highly important to deeply understand the potential impacts of the future climate on post-rainy sorghum crop performance in India. Researchers have attempted to comprehend this with either one or two future climate change scenarios previously. There is scanty information or evidence on plausible climate change impacts on the crop using a whole range (multi-model) of climate change projections previously.
There is scanty information or evidence on plausible climate change impacts on the crop using a whole range (multi-model) of climate change projections. It would be highly interesting to see and understand the entire gamut of those plausible impacts under diverse sorghum agro-ecological conditions in India. This will immensely help us to define and develop location-specific and tailor-made climate change mitigation strategies and management practices well in advance.
The present research paper makes robust and systematic efforts to quantify the plausible future climate change impacts on post-rainy sorghum performance in India using both crop simulation and multi-model climate scenarios. This exercise will showcase the potential climate change impacts on postrainy sorghum crops across the studied states in India. The findings in this paper will help scientists, agronomists, and policymakers in designing suitable climate adaptation strategies and policies for crop improvement.
The outcome of this paper will help in protecting the livelihoods of millions of rainfed farmers who are directly or indirectly dependent on post-rainy sorghum cultivation in India and their associated livestock population. The lessons learned in India could be scaled up to other similar regions around the world.
Read the study:
Chadalavada K, Gummadi S, Kundeti KR, Kadiyala DM, Deevi KC, Dakhore KK, Bollipo Diana RK, Thiruppathi SK. (2022) Simulating Potential Impacts of Future Climate Change on Post-Rainy Season Sorghum Yields in India. Sustainability 14(1):334.
