Free-air Carbon Dioxide Enrichment System Research Articles

Effects of free‐air CO2 enrichment and drought on root growth of field grown maize and sorghum

AbstractIncreasing CO2 concentration ([CO2]) is thought to induce climate change and thereby increase air temperatures and the risk of drought stress, the latter impairing crop growth. The objective of this study was to investigate the effects of elevated [CO2] and drought stress on root growth of one maize genotype (Zea mays cv. Simao) and two sorghum genotypes (Sorghum bicolor cv. Bulldozer and Sorghum bicolor × Sorghum sudanense cv. Inka) under the cool moderate climate of Central Europe. It was hypothesized that root growth stimulation due to elevated [CO2] compensates for a reduced root growth under drought stress. Therefore, we established an experiment within a free‐air carbon dioxide enrichment system (FACE) in 2010 and 2011. Sorghum and maize genotypes were grown under ambient [CO2] (385 ppm CO2) and elevated [CO2] (600 ppm CO2) and in combination with restricted and sufficient water supply. Elevated [CO2] decreased root length density (RLD) in the upper soil layers for all genotypes, but increased it in deeper layers. Higher [CO2] enhanced specific root length (SRL) of “Simao” and “Bulldozer,” however, did not affect that of “Inka.” “Simao” achieved a higher SRL than the sorghum genotypes, indicating an efficient investment in root dry matter. Although elevated [CO2] affected the root growth, no interaction with the water treatment and, consequently, no compensatory effect of elevated [CO2] could be identified.

Changing climate and potential impacts on potato yield and quality ‘CHIP’: introduction, aims and methodology

Climate change effects caused by an increasing concentration of CO 2 and ozone represent an issue of major concern both for scientists and policy-makers. In a concerted program funded by the Commission of the European Union, a European network of experiments (in open-top chambers (OTC), and free air carbon dioxide enrichment systems (FACE)) and modelling was carried out to investigate the effects of increasing atmospheric CO 2 and ozone concentrations, under different climatic conditions, on potato ( Solanum tuberosum L. cv. Bintje). This contribution describes the experimental network and the standard protocol set-up for the assessments that served to improve and to validate process oriented potato growth simulation models leading to scenarios of future productivity of potato in Europe.

A New Field Technique for Elevating Carbon Dioxide Levels in Climate Change Experiments

1. A compact, low-cost, free-air carbon dioxide enrichment system for use in climate change experiments is described. The system has been used in a small-scale study of the effects of an enriched carbon dioxide atmosphere on the growth and functioning of a natural plant community. 2. The experiment ran for 4 months in summer on a nutrient-poor limestone grassland in Derbyshire. The study examined the separate and combined effects of elevated CO 2 , temperature and soil nutrient status on the growth of seedlings of obligate mycorrhizal and non-mycorrhizal plant species native to the site. 3. It was demonstrated that the CO 2 elevation could be controlled within the limits set for 64% of the time. Significant effects of elevated CO 2 on the growth and recruitment of seedlings were found in the presence of added nutrients and elevated temperatures.