Interactive effects of soil acidification and phosphorus deficiency on photosynthetic characteristics and growth in Juglans regia seedlings

Aims Our main purposes were to explore effects of phosphorus deficiency and soil acidification on growth, water balance and phosphorus nutrition in Juglans regia seedlings and to investigate the hydraulic mechanism involved in reduced photosynthesis and growth. Methods We measured growth, hydraulic characteristics, and gas exchanges in J. regia seedlings. The effects of phosphorus deficiency and soil acidification on xylem anatomic structure, water balance and photosynthetic characteristics were also analyzed. Important findings Soil acidification inhibited the phosphorous uptake and utilization efficiency in J. regia seedlings. A combination of soil acidification and phosphorous deficiency interrupted water balance, and reduced photosynthesis and growth of J. regia seedlings. Under soil acidification and phosphorus deficiency, non-stomatal factors also played a role in inhibiting photosynthesis.