Modeling climate change impact on dryland wheat production for increased crop yield in the Free State, South Africa, using GCM projections and the DSSAT model

IF 3.3 3区环境科学与生态学 Q2 ENVIRONMENTAL SCIENCES

Frontiers in Environmental Science Pub Date : 2023-07-17 DOI:10.3389/fenvs.2023.1067008

Caroline F. Ajilogba, S. Walker

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引用次数: 0

Abstract

Introduction: The impact of climate change on food production in South Africa is likely to increase due to low rainfall and frequent droughts, resulting in food insecurity in the future. The use of well-calibrated and validated crop models with climate change data is important for assessing climate change impacts and developing adaptation strategies. In this study, the decision support system for agrotechnology transfer (DSSAT) crop model was used to predict yield using observed and projected climate data.Materials and Methods: Climate, soil, and crop management data were collected from wheat-growing study sites in Bethlehem, South Africa. The DSSAT wheat model (CROPSIM-CERES) used was already calibrated, and validated by Serage et al. (Evaluating Climate Change Adaptation Strategies for Disaster Risk Management: Case Study for Bethlehem Wheat Farmers, South Africa, 2017) using three wheat cultivar coefficients obtained from the cultivar adaptation experiment by the ARC-Small Grain Institute. The model was run with historical climate data for the eastern Free State (Bethlehem) from 1999 to 2018 as the baseline period. To determine the effects of climate change, the crop model simulation for wheat was run with future projections from four Global Climate Models (GCM): BCC-CSM1_1, GFDL-ESM2G, ENSEMBLE, and MIROC from 2020 to 2077.Results: The average wheat yield for the historic climate data was 1145.2 kg/ha and was slightly lower than the highest average yield of 1215.9 kg/ha from GCM ENSEMBLE during Representative concentration pathways (RCP) 2.6, while the lowest yield of 29.8 kg/ha was produced during RCP 8.5 (GCM GFDL-ESM2G). Model GFDL-ESM2G produced low yields (29.8–47.74 kg/ha) during RCP 8.5 and RCP 6.0, respectively. The yield range for GCM BCC-CSM1_1 was 770.2 kg/ha during RCP 2.6 to 921.68 kg/ha during RCP 4.5 and 547.84 kg/ha during RCP 8.5 to 700.22 kg/ha during RCP 2.6 for GCM MIROC.Conclusion: This study showed a declining trend in yield for future climate projections from RCP2.6 to RCP8.5, indicating that the possible impacts of higher temperatures and reduced rainfall in the projected future climate will slightly decrease wheat production in the eastern Free State. Adaptation measures to mitigate the potential impact of climate change could include possible changes in planting dates and cultivars. Using a crop model to simulate the response of crops to variations in weather conditions can be useful to generate advisories for farmers to prevent low yield.

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利用GCM预估和DSSAT模式模拟气候变化对南非自由邦旱地小麦产量的影响，以提高作物产量

引言：由于降雨量低和干旱频繁，气候变化对南非粮食生产的影响可能会增加，导致未来粮食不安全。使用具有气候变化数据的经过良好校准和验证的作物模型对于评估气候变化影响和制定适应战略非常重要。在本研究中，农业技术转让决策支持系统（DSSAT）作物模型用于利用观测和预测的气候数据预测产量。材料和方法：从南非伯利恒的小麦种植研究点收集气候、土壤和作物管理数据。Serage等人已经校准并验证了所使用的DSSAT小麦模型（CROPSIM-CERES）。（评估灾害风险管理的气候变化适应策略：南非伯利恒小麦农民的案例研究，2017）使用了ARC小谷物研究所品种适应实验中获得的三个小麦品种系数。该模型以1999年至2018年东部自由邦（伯利恒）的历史气候数据为基准期运行。为了确定气候变化的影响，对小麦的作物模型模拟使用了四个全球气候模型（GCM）的未来预测：BCC-CSM1_1、GFDL-ESM2G、ENSEMBLE，和2020年至2077年的MIROC。结果：历史气候数据的平均小麦产量为1145.2公斤/公顷，略低于代表浓度途径（RCP）2.6期间GCM ENSEMBLE的最高平均产量1215.9公斤/公顷。而RCP 8.5期间的最低产量为29.8公斤/公顷（GCM GFDL-ESM2G）。GFDL-ESM2G型在RCP 8.5和RCP 6.0期间分别产生低产量（29.8–47.74公斤/公顷）。GCM BCC-CSM1_1在RCP 2.6期间的产量范围为770.2公斤/公顷，在RCP 4.5期间为921.68公斤/公顷；GCM MIROC在RCP 8.5期间为547.84公斤/公顷至RCP 2.6期间为700.22公斤/公顷。结论：这项研究显示，从RCP2.6到RCP8.5，未来气候预测的产量呈下降趋势，表明在预测的未来气候中，气温升高和降雨量减少的可能影响将略微降低自由州东部的小麦产量。缓解气候变化潜在影响的适应措施可能包括种植日期和品种的可能变化。使用作物模型来模拟作物对天气条件变化的反应，有助于为农民提供预防低产的建议。

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来源期刊

Frontiers in Environmental Science Environmental Science-General Environmental Science

CiteScore

4.50

自引率

8.70%

发文量

2276

审稿时长

12 weeks

期刊介绍： Our natural world is experiencing a state of rapid change unprecedented in the presence of humans. The changes affect virtually all physical, chemical and biological systems on Earth. The interaction of these systems leads to tipping points, feedbacks and amplification of effects. In virtually all cases, the causes of environmental change can be traced to human activity through either direct interventions as a consequence of pollution, or through global warming from greenhouse case emissions. Well-formulated and internationally-relevant policies to mitigate the change, or adapt to the consequences, that will ensure our ability to thrive in the coming decades are badly needed. Without proper understanding of the processes involved, and deep understanding of the likely impacts of bad decisions or inaction, the security of food, water and energy is a risk. Left unchecked shortages of these basic commodities will lead to migration, global geopolitical tension and conflict. This represents the major challenge of our time. We are the first generation to appreciate the problem and we will be judged in future by our ability to determine and take the action necessary. Appropriate knowledge of the condition of our natural world, appreciation of the changes occurring, and predictions of how the future will develop are requisite to the definition and implementation of solutions. Frontiers in Environmental Science publishes research at the cutting edge of knowledge of our natural world and its various intersections with society. It bridges between the identification and measurement of change, comprehension of the processes responsible, and the measures needed to reduce their impact. Its aim is to assist the formulation of policies, by offering sound scientific evidence on environmental science, that will lead to a more inhabitable and sustainable world for the generations to come.