Change in net photosynthesis of narrowleaf lupine plants under the effect of soil temperature

The effect of soil temperature on CO₂ exchange of intact narrowleaf lupine variety Siderat 38 plants depending on illumination level and air temperature is studied in a multifactorial experiment under controlled environmental conditions. It is shown that the strength of influence of soil temperature on net photosynthesis of plants depends to a considerable extent on air temperature and to a lesser degree on illumination.