Effects of light intensity on nitrogen economy of spring barley (Hordeum distichum L.).

Abstract

In a pot experiment in a phytotron, barley cv. Trumpf seedlings were grown at a light intensity of 6.50 MJ/msuperscript 2 for 40 d and then at light intensities of 6.50, 4.33 or 1.86 MJ/msuperscript 2 with a 14-h day. 134 mg N/plant was applied in 3 dressings at 2 d before emergence and 26 and 48 d after emergence. N uptake was only slightly affected by light intensity. DM yield/plant increased with increasing light intensity. 101 mg DM/mg N was obtained at a light intensity of 1.86 MJ/msuperscript 2 and 175 mg DM/mg N at 6.50 MJ. Higher light intensity accelerated leaf senescence and shortened the photosynthetically active period by restricting N concn. N harvest index was reduced at the lowest light intensity. (Abstract retrieved from CAB Abstracts by CABI’s permission)