Influence of nutrition on vegetation response to carbon dioxide. I. Interactions of nitrogen and phosphorus supply on soybean growth and nutritional parameters. [Glycine max (L. ) Merr]

The responses to elevated levels of atmospheric carbon dioxide (CO/sub 2/) of soybean as the classic example of the highly bred, rapidly growing agricultural species under adequate as well as growth-limiting levels of available phosphorus (P) and nitrogen (N) were studied. Our objective was to quantify nutrient uptake responses to elevated CO/sub 2/ as well as carbon acquisition and partitioning responses in a range of P and N availability, under carefully controlled conditions. This report summarizes preliminary findings from a growth study in which non-nodulating 'Lee' soybeans were grown to harvest maturity at 5 levels of N and five levels of P and at 350 and 700 ppM CO/sub 2/.