Comparison between net and gross root production by winter wheat and by perennial ryegrass

Abstract

Field rhizotrons were used to estimate gross and net production of roots by wheat (Triticum aestivum L.) and perennial ryegrass (Lolium perenne L.) grown under the same management systems. The maximum instantaneous length of living roots observed in the topsoil (to 26 cm depth) was considerably less than the maximum gross production. This difference amounted to (36 ± 3) % and (45 ±4)% for wheat and ryegrass respectively. Mean longevity for wheat roots was (59 ± 7) days, whereas that for ryegrass was (46 ± 5) days. Future studies of root production and the carbon balance of graminaceous species should pay close attention to the turnover of roots.