These values can be used to estimate the amount of carbon dioxide assimilated into carbohydrates. For each gram of carbon dioxide assimilated about 0.614 g of carbohydrate is produced. Above the saturation point, photosynthetic rates will level off or decrease. The compensation point is achieved when photosynthesis exceeds respiration. Bright sunlight has an intensity of approximately 500 W m -2 .
Excess sunlight can actually inhibit photosynthesis.
The remaining energy is lost through reflection off of the leaves, conversion to heat and it dissipation through conduction or evapotranspiration. Plant Production in Arid Environments Plants lose water in direct proportion to the carbon dioxide they assimilate. Usually nitrogen is limiting and its addition will increase productivity. Phosphorus may also be a limiting nutrient, but its application may not lead to an increase in productivity, especially if nitrogen is absent. In some cases, nitrogen-fixing bacteria in symbiotic relationship with a particular species of plant ensure that nitrogen is not limiting.