An Econometric and Agro-meteorological Study on Rain-fed Wheat and Barley in Turkey Under Climate Change

Abstract

The objective of our study is to project the impacts of climate change on rain-fed wheat and barley production in Turkey for 2070–2079 and identify their policy implications. We first estimate the wheat and barley yield and area sown functions for the Konya and Adana provinces, which have been representative wheat and barley production areas in Turkey. Most of the wheat and barley in Turkey have been produced in rain-fed conditions. Rain-fed arable land in Turkey is either planted to wheat or barley, leading Turkish farmers to make planting decisions according to the relative price of these crops. The relative price reflects the previous year’s Turkish demand for and supply of both crops, and of animal products produced by using barley as feed. As expected from the rain-fed, traditional and low input wheat and barley production in Turkey, most of the estimated yield and area sown functions for these crops have statistically significant correlation coefficients to spring heat-damage variables and drought-damage variables, as well as to the cumulative monthly rainfall variables. Iterative estimation methods were used for selecting the best correlation coefficients of these variables. These coefficients not only appropriately reflect the severe fragility in the rain-fed wheat and barley production on the rain-fed arable land in Konya and Adana, but also provide a good basis for estimating the 2070s’ wheat and barley production using the monthly temperature and rainfall projected by a regional circulation model (RCM) in our study for that period. We think that the impact of climate change on crop yield and area sown in the real world is determined not only by the crop responses, but also by farmers’ adaptations and agricultural experiment stations’ research adaptations to climate change. This is affected by the changes in demand for and supply of wheat, bread, barley and animal products, reflected in the relative price between wheat and barley in the previous year, as well as by policy and institutional changes. Our model incorporates most of these aspects explicitly and implicitly. Thus, we can conclude that the process to assess the impacts of climate change on wheat and barley production in Turkey using our model better emulates the real world process than the physiological plant growth model that focuses the impacts of climatic change on mainly the growth of wheat and barley. Consequently, we insert the 2070–2079 monthly rainfall and temperature data projected by the RCM into the estimated yield and area sown functions in order to project wheat and barley production for that period. Then, adding the FACE 2 * CO2 fertilisation effect of 13% to the projected yields, the final change rates in the wheat and barley production projected for the 2070–2079 period are −14% for wheat and −28% for barley in Konya, and −0.46% for barley and +3.5% for wheat in Adana. The projected impacts of climate change on wheat and barley production in Turkey can be calculated as weighted averages of these impacts with production weights for Central Anatolia and its peripheral region, where the regions of Konya and Adana are the typical representative areas. The impact of climate change on wheat production in Turkey is −12.06% of current production. For barley this impact is −14.39%. Given the self-sufficient wheat and barley market of Turkey, these impacts may cause a food crisis in the case of wheat, and severe shortage of feed and livestock products in the case of barley in Turkey. We suggest the development and use of new wheat and barley varieties that are resistant to spring heat damage and drought and preparation of the economic and political capabilities to import the needed wheat and barley that have been staple foods for Turkish people for thousands of years.