Weatherproofing for a smarter, resilient and more sustainable agri-sector

Raymond, Joanna (2023) Weatherproofing for a smarter, resilient and more sustainable agri-sector. Doctoral thesis, University of East Anglia.

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Abstract

Agricultural production is highly vulnerable to climate change. Warming global temperatures, increased frequency of extreme weather events, such as flash flooding, and shifts in the ranges of crop pathogens highlight current agroclimate challenges faced in the 21st century. In the mid-1990s, the UK observed plateaus in yields of staple crops including wheat (Triticum aestivum L.), and in recent years, strong yield impacts of high interannual weather variability have been observed nationally. To meet the growing demand for food and increase domestic production, there is an urgent need to increase the climate resilience of key cereal crops and the broader agri-food sector.

This thesis explores how crop breeding and changes in weather and climate variables important to agriculture, i.e. the agroclimate, have contributed to cereal yield variability in the UK. In the first State of the UK Agroclimate, trends and variability in national yields and key agroclimate metrics are quantified for 1981-2020 to allow growers and farmers to make climate-informed decisions on crop and variety choices. Incorporating historical time-series records of these agroclimate metrics into statistical models with variety trials data establishes their relative importance in determining winter wheat yields and enables variety sensitivity to each metric to be investigated. In doing so, methods of identifying climate-resilient crop varieties are presented. The contribution of plant breeding to national cereal yields is quantified through the calculation of genetic gain. Given the importance of this metric for the evaluation of success of plant breeding programmes and for funding allocation, the sensitivity and robustness of this metric is explored.

Changes in the UK agroclimate provide both risks and opportunities for cereal growers. The increase in solar radiation during grain fill observed in the South-East of the UK was shown to be beneficial for winter wheat yields, whilst increasing interannual yield variability has contributed to overall stagnation in yields in the last decade. Long-term warming trends have contributed to cereal drilling dates getting earlier, extending the growing season. However, in years of high autumn rainfall, delays in planting, a shortening of the growing season and lower yields were observed. Comparing national and variety trial yield trends shows that crop breeding is responsible for over 95% of yield increases over the last 30 years, however, to further optimise yield increases there is a need to grow varieties that perform best based on local climatic conditions. Use of case study datasets extracted from the variety trials data showed that genetic gain is sensitive to a number of factors, including the choice and number of long-term “check” varieties included in a variety trials programme. Recommendations are made on how best to calculate the metric.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Environmental Sciences
Depositing User:	Chris White
Date Deposited:	18 Dec 2024 11:28
Last Modified:	18 Dec 2024 11:28
URI:	https://ueaeprints.uea.ac.uk/id/eprint/98025
DOI:

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