Estimation of water requirements of pearl millet under different climate change scenarios (Under Different RCP Scenarios) for semi-arid region of Hisar, Haryana

Introduction

Pearl millet (Pennisetum glaucum) is an important cereal crop widely cultivated in arid and semi-arid regions of Asia and Africa. It is well known for its exceptional tolerance to drought, high temperature, and low soil fertility, making it a suitable crop for marginal environments where other cereals often fail. Because of its adaptability to harsh climatic conditions, pearl millet plays a crucial role in ensuring food and nutritional security in many developing countries (Yadav et al., 2012) [6] . In India, pearl millet (commonly known as bajra) is a major staple food and fodder crop, particularly in the semi-arid regions of Rajasthan, Haryana, Gujarat, and Maharashtra. The crop is primarily grown during the kharif season, relying mainly on monsoon rainfall. Apart from being a staple food, pearl millet grains are rich in proteins, minerals, and dietary fiber, while the crop residues serve as valuable fodder for livestock, making it an integral component of croplivestock farming systems (ICAR, 2017) [2] . Water is one of the most critical inputs influencing crop growth, productivity, and sustainability in agriculture. Efficient irrigation management requires accurate estimation of crop water requirement and evapotranspiration. According to the guidelines provided by the Food and Agriculture Organization (FAO), crop water requirement is generally determined using reference evapotranspiration and crop coefficients under specific climatic conditions (Allen et al., 1998) [1] .

Climate change is expected to significantly affect agricultural production systems through changes in temperature, precipitation patterns, and evapotranspiration rates. Future climate projections are commonly represented using Representative Concentration Pathways (RCPs), which describe different greenhouse gas concentration trajectories. These scenarios are widely used in climate impact studies to assess potential changes in crop water demand and irrigation requirements (IPCC, 2014) [3] . Therefore, estimating the water requirement of pearl millet under different RCP scenarios is essential for developing climate-resilient irrigation strategies and sustainable water resource management. CROPWAT model is an effective tool in recent time to estimate the water requirement of a crop under projected scenarios of future (Thimme et al, 2013) [5] and (Thanoon et al, 2019) [4] .

Materials and Methods

The study was conducted in the field of CCS HAU Hisar during kharif season 2023. The study area is located with an elevation of 215.2 meters above the mean sea level and located between of 29° 10'N latitude and 75° 46' E longitude. District Hisar of Haryana is located in India's semi-arid, subtropical climate zone. Climate of this place is primarily characterized by temperature extremes, little rainfall and dryness. The soils of this region are derived from Indo-Gangetic alluvium, which are very deep and sandy loam in texture and have some amount of calcium carbonate (CaCO 3 ) in the soil profile. The soil of experimental field station was sandy loam in texture and belongs to Entisols soil order. Soil has mechanical composition of Sand (56.7%), Silt (25.8%) and Clay (17.8%).

Experimental details

The experiment uses FRBD (Factorial Randomized Block Design) design with four replications. Three dates of sowing were selected for the crop i.e., 30 th June, 13 th July and 27 th July and three varieties were taken GHB 558, HHB 67 Improved and HHB 299 with four replications. Crop was examined at each phenophase from emergence to harvesting. Projection of irrigation water requirement using CROPWAT 8.0 model for Hisar, Haryana Crop evapotranspiration, effective rainfall and Irrigation water requirement for pearlmillet crop was projected using CROPWAT 8.0 for Hisar district of Haryana and projected values shows that there would be increase in the effective rainfall for the periods viz., 2040s, 2060s and 2080s over baseline period. By RCP 2.6, the irrigation requirement for the pearl millet crop was higher during the period 2020-2040 (26.2 mm, 12.3 mm, 26.1 mm) for all sowing dates than other two periods i.e., 2060s and 2080s for the three different growing environments (30 th June, 13 th July, 27 th July) shown in table 2.

The details of experiment are given below

Results and Discussion

Conclusion

Crop water irrigation requirement was projected using CROPWAT 8.0 model for the major pearl millet growing districts of Haryana (Hisar). It was projected that there would be more water requirement during the period of 2020-2040 under RCP 2.6 and higher water requirement during the period of 2060-2080 under RCP 8.5 for all the three dates of sowing for the district Hisar. The requirement would be less in such periods because of more amount of effective rainfall during this time compared to the baseline period of the district individually. CROPWAT model projected, that there would be more irrigation water requirement during the period of 2020-2040, under RCP 2.6 and higher during the period of 2060-2080, under RCP 8.5 for all the three growing environments, for Hisar district.

References

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2. Indian Council of Agricultural Research. Handbook of agriculture. New Delhi (India): Indian Council of Agricultural Research; 2017.
3. Intergovernmental Panel on Climate Change. Climate change 2014: Impacts, adaptation, and vulnerability. Geneva (Switzerland): Intergovernmental Panel on Climate Change; 2014.
4. Thanoon AA. Effect of irrigation scheduling using CROPWAT on water use efficiency and grain yield and components for maize (Zea mays L.) in semi-arid regions. Al-Rafidain Engineering Journal. 2019;24(2):130-137.
5. Thimme Gowda P, Manjunaththa SB, Yogesh TC, Sunil AS. Study on water requirement of maize (Zea mays L.) using the CROPWAT model in the Northern Transitional Zone of Karnataka. Journal of Environmental Science, Computer Science and Engineering and Technology. 2013;1:105-113.
6. Yadav OP, Rai KN, Rajpurohit BS, et al. Pearl millet: Genetic improvement and production. Jodhpur (India): ICAR-All India Coordinated Research Project on Pearl Millet; 2012.