Effects of elevated CO2 on growth parameters and crop quality of soybean (Glycine max [L.] Merr.) grown in fly-ash amended soils

RODRIGUEZ, J.H.; KLUMPP A.; FANGMEIER A.; HÖGY P.; LAMARQUE, A.; MAESTRI, D.M.; PIGNATA, M.L.

Mar del Plata, Argentina

Congreso; II Congreso Argentino de la Sociedad de Toxicología y Química ambiental (SETAC), VI Reunión SETAC en Argentina “Avance en Toxicología y Química ambiental”; 2008

SETAC

Effects of Elevated CO2 on Growth Parameters and Crop Quality of Soybean (Glycine max [L.] Merr.) Grown in Fly-Ash Amended Soils   Rodriguez J.H.1, Klumpp A.3, Fangmeier A.3, Högy P.3, Lamarque A.2, Maestri D.M.2 and Pignata M.L.1.   1Área Bioindicadores y Contaminación, 2Área Fitoquímica Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, Argentina. 3 Institut für Landschafts- und Pflanzenökologie, Universität Hohenheim, Deutschland. jrodriguez@com.uncor.edu   Soybean (Glycine max [L.] Merr.) is the main crop per cultivated area, production volume and gross value in the Province of Córdoba (Argentina) like in many regions worldwide. Predicted increases of atmospheric CO2 concentrations due to anthropogenic emissions may significantly influence agricultural yield because CO2 as a primary substrate for photosynthesis will stimulate growth of C3 crop species. On the other hand, large areas in Córdoba present elevated levels of toxic elements, such as heavy metals, in air, water and soil due to industrial activities. This situation implies a serious risk for the health of the population and the consumers of food produced there. In order to investigate the interactions of CO2 and heavy metals, soybean was grown in standard soil amended with different proportions of fly-ash (0%, 1%, 10%, 15%, 25% w/w) from a coal-fired power plant. The soybeans were exposed in climatic chambers to two concentrations of CO2 (400 and 600 ppm) from emergence to seed maturity simulating the climatic conditions of Córdoba. Ten morphological parameters, aboveground and root biomass, as well as pigment, carbohydrate, oil (seeds), fatty acid and total soluble protein (seeds and leaves) concentrations were determined at three growth stages (vegetative, reproductive/grain filling, maturity). The results revealed that elevated CO2 caused a stimulation of all growth parameters whereas no significant differences were found in fatty acids concentrations. When evaluating the combination of CO2 and different fly-ash concentrations, the plants grown in soils with higher proportion of fly-ash showed a reduction in growth, while the oil yield was higher in these treatments. The data demonstrate that in areas burdened with heavy metals soybean growth can be adversely affected despite the CO2 fertilization effect. Seed quality measured as oil yield and protein contents, by contrast, may depend on the quantity and quality of the fly-ash amended soil.   Keywords: Glycine max; food quality; CO2; heavy metals.