Abstract:
Future vegetable crop production might be affected by Climate Change with the projected increase in atmospheric CO2 concentration and changes in precipitation pattern. Elevated CO2 as one main component of photosynthesis is assumed to increase the yield of many crops while alleviating negative effects of drought stress and, thereby, increasing the water use efficiency. However, the responses of field grown vegetable crops to elevated CO2 are still unknown as previous findings are mainly derived from experiments conducted under controlled environments. In addition, the field vegetable production is characterized by several sets per season, varying growth conditions during the production periods and a high water demand usually provided by an irrigation system. Moreover, vegetable crops differ in the harvest organs, e.g. fruits, root tuber, bulbs or leaves, which are predominantly harvested in an early development stage. These vegetable-specific aspects have not been considered in past Free Air Carbon Dioxide Enrichment (FACE) experiments. Therefore, we aim at analyzing the short and long impacts of elevated CO2 with limited water supply on field vegetable crop productivity for three different crops (Cucumis sativus L., Raphanus sativus var. sativius L., Spinacia oleracea L.). Here, we present the methodological framework. Experiments will be conducted in the newly established FACE facility for vegetable crops at Geisenheim University, Germany. The facility is designed to raise the ambient CO2 concentration at the experimental field site by about 20% to approximately 480 ppm and to regulate the water supply with a drip irrigation system, resulting in a split plot design with three replications. In each replication an annual crop rotation with several production cycles of the three different vegetable crops are realized. Measurements of the CO2 and H2O gas exchange on leaf level as well as non-destructive and destructive recordings of plant growth and development are planned.
