His research, which focused on the regrowth of the plant, reveals that alfalfa grows more with elevated concentrations of carbon dioxide (CO2), in particular when this condition coincides with high temperatures. The effects can be affected by other variables, such as the availability of water in the soil, which would reduce its growth and can modify its response to CO2. In addition, in the study it was confirmed that the process of photosynthesis can be stimulated or reduced by CO2, depending on the growth phase of the plant.
Variability in the responses
As this study highlighted, one of the most interesting aspects of this type of plant is the increase in nutrient storage in the roots, especially of proteins, when the plant is periodically cut back. These nutrient reserves contribute to rapid regrowth and to maintaining the perenniality of this crop. Similarly, it has been shown that a moderately dry climate maintained over time favors the accumulation of these reserve proteins, which can stimulate the growth of the plants during the following regrowth.
The results show the great variability of plant response to increases in CO2. Thus, a greater availability of CO2, which in principle should stimulate growth through increase photosynthesis, when it interacts with other variables such as the temperature or availability of water, can modify significantly the response of the alfalfa, depending on its stage of growth.