The Impact of Climate Change on the Growing Season of Vegetable Crops in Dhi Qar Governorate

Abstract

This study aims to analyse the impact of climate change on the growing season of vegetable crops in Dhi Qar Governorate by examining selected summer and winter vegetable crops through two main axes. The first axis involved analysing climatic factors (solar radiation, minimum and maximum temperatures, rainfall, relative humidity) based on climate cycles to assess changes over the study period. The second focus centred on assessing the impact of these climatic changes on the thermal suitability of the growing season, where daily data on minimum and maximum temperatures for each crop were analysed and compared with the minimum and maximum thermal limits suitable for the growth of the crops studied, which included summer vegetable crops (aubergines, okra, aubergines, and watermelons) and winter crops (lettuce, spring onions) to determine the suitability of climatic conditions during the growing seasons in Dhi Qar Governorate. Results showed a general trend towards higher solar radiation and temperatures, accompanied by a decrease in relative humidity and a decline in rainfall, particularly during the final years of the study period. These changes have affected planting dates and growing season conditions, as it was found that March is characterised by varying suitability for the growth of aubergines, okra, and watermelon, as minimum temperatures remain within relatively acceptable limits, whilst maximum temperatures fall short of the optimum level, leading to a poor growth response from these crops during this month. Suitable conditions gradually improve during April, becoming more conducive to growth as temperatures approach the optimum range. The study also showed the study indicates that September is unsuitable for the growth of summer crops, as maximum temperatures exceed the upper suitable limit, leading to heat stress that negatively affects growth and productivity. As for winter vegetable crops (lettuce and spring onions), it was found that October is unsuitable for growth due to maximum temperatures exceeding the optimal thermal limits and the lack of suitable thermal conditions for sufficient periods. It is clear from this that farmers need to adopt flexible agricultural strategies that are compatible with climatic conditions by adjusting planting dates—either earlier or later—according to the appropriate thermal requirements of each crop, to ensure healthy crop growth and minimise climate-related risks that may affect productivity or cause damage to the crop.