The development of better soil and water management procedure requires understanding of plant response to various soil water relationships. It is especially important to know how the water status of plants, as affected by soil suction, influences the rate of important metabolic and synthetic reactions. This paper reports the results of a preliminary study on the effects of soil water content on the rate of photosynthesis, the exceedingly important reaction through which plants manufacture carbohydrates from atmospheric carbon dioxide (CO₂).