Abstract:

In many regions of the world, climate change is expected to have severe impacts on agricultural systems. As many previous impact studies suggest, yields could decrease, water resources may decline, and erosion risk could increase. Climate change is likely to alter agro-climatic conditions with distinct regional patterns, which necessitates adaptation measures that are adjusted to local characteristics. The objective of this study was to identify agricultural land management adaptation measures with regard to indicators reflecting major aspects of four important agricultural functions: crop yield, soil erosion by water, nutrient leaching, and water use. Changes in land management are one way to adapt to future climatic conditions, including declining water resources. Systematic explorations of land management possibilities using optimization approaches were so far mainly restricted to studies of land and resource management under constant climatic conditions. In this study, we bridge this gap and exploit the benefits of multi-objective regional optimization for identifying optimum land management adaptations to climate change. We consider two climate scenarios for 2050 in the Lakes Prespa watershed. We designed a multi-objective optimization routine that integrates a generic crop model in combination with spatial information on soil, climate conditions and slope at a 500 m x 500 m resolution. The results demonstrate that even under the more extreme climate scenario compromise solutions maintaining productivity at the current level with minimum environmental impacts in terms of erosion and nitrogen leaching are possible. Necessary management changes include (i) adjustments of crop shares, i.e. increasing the proportion of early harvested winter cereals at the expense of irrigated spring crops, (ii) widespread use of reduced tillage, and (iii) allocation of irrigated areas to soils with low water-retention capacity at lower elevations. It is concluded that the potential for climate change adaptation at the regional scale is significant. Overall, this study shows that negative climate change impacts on agro-ecosystems can be limited to a large extent by adaptation. However, such adaptation measures are expected to cause a sharp increase in the region’s agricultural water demand. The results could serve as basis for planners and decision makers to develop suitable regional land use strategies.

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