Evaluation of management options to enhance climate resilience in pearl millet production system using system analysis approach

Abstract

ABSTRACT Agriculture is significantly affected by temperature variability and other climatic variables. Pakistan is located among one of the most vulnerable regions to climate change and variability, which directly affects growth and yield of crops and the livelihood of rural communities. Evaluation of best management practices is a current problem for pearl millet in Pakistan to overcome climate change impacts in future, as it is ignored due to focus on other major cereals. Management practices like planting time, plant population, and nitrogen fertilization strategies are among the most important factors affecting yield of pearl millet in Pakistan. While pearl millet is a hardy and idyllic for environments prone to different environmental stresses. This crop continues to produce highly nutritious grain sustainably, thereby encouraging the fight against poverty and food insecurity due to its resilience to climate change. Systems analysis approach is a suitable approach to advance our understanding on the effects of climate change and climate variability on crops growth and yield. Hence, two field experiments were conducted at Agronomic at the Agronomic Research Area, University of Agriculture, Faisalabad and Agronomic Research Station, Karor Lal Eason, District Layyah under irrigated semi-arid and arid conditions over a period of two summer seasons (2015-16). The results elucidated that planting time, intra row spacing and nitrogen rate significantly affected crop development, yield and yield attributes at Faisalabad and Layyah. The earlier and late planting resulted in late anthesis and maturity of pearl millet at both locations, while planting of millet in the month of July showed less days to panicle initiation, anthesis and maturity. Intra row spacing did not affect significantly on phenology of millet at both locations. In case of nitrogen application, higher rate of N application delayed the maturity of millet. All recorded observations performed better, when pearl millet was planted during 3rd week of June and 1st week of July at plant spacing of 15 cm at Faisalabad and during month of July at Layyah. The results also illustrated that higher grain yield of millet can be achieved by optimizing resources; nitrogen rate (150 kg N ha-1) through empirical modeling, which were explored using quadratic equations to optimize requirement of nitrogen for pearl millet under semi-arid and arid environments. The optimum N rate gave higher ANUE. Model for path analysis was developed by selecting the important yield components, which directly or directly affected the yield of millet. Correlations of grain yield with yield components indicated that the grain weight per panicle is more associated with millet yield during both years, locations and studies. CSM-CERES-Millet model was calibrated and the accuracy in performance of model was checked under contrasting environments. The calibrated millet model was also used to quantify the climate change assessment and its impact on millet yield for mid-century scenarios under RCP4.5 and 8.5. The climate resilient cultivars were developed using adaptation strategy for Faisalabad and Layyah to fight the impact of future climate on grain yield of millet. High correlation coefficient (0.90 to 0.99) of observed and projected Tmax and Tmin in two models were projected, whereas precipitation values showed much lower correlations for three decades (2017-2026, 2027-2036 and 2037-2046). The changes in projected variables showed 8-11% decrease in millet yield at Faisalabad and Layyah. About 11% reduction in millet yield were predicted using Genetic Algorithm, while model projected 14-19% reduction in millet yield up to under RCP 8.5. However, introducing climate resilient millet cultivar can reverse the climate change impacts by increasing yield from 12-24% under semi-arid and arid environments of Punjab.