Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/20/2004
Publication Date: 11/5/2004
Citation: Reeve, J., Smith, J.L., Carpenter-Boggs, L., Reganold, J.P. 2004. Plant uptake of organic molecules as an n source. Soil Science Society of America Annual Meeting.
Technical Abstract: Uptake of organic nitrogen such as amino acids and soluble proteins by plants has become a topic of growing interest in recent years. We are conducting research to determine whether wheat grown in soil fertilized with organic N utilizes more organic N directly than wheat grown with inorganic N. We are also testing for differences in uptake of amino acids between pre 1930's varieties, modern varieties and wild relatives of wheat to determine whether this trait has been selected against by breeding under high inorganic N inputs. Preliminary trials using 14C labeled glycine were conducted to determine effects on uptake of wheat seedlings (vars Madson and Arco) grown in Hoagland solution, 10% Hoagland solution, 100 mM glycine or water and to determine uptake concentration curves. Uptake ranged from 2.180 to 1.189 ug glycine / mg root and 0.496 to 0.091 ug glycine / mg shoot. Uptake by roots was highest in seedlings grown in water, but highest in shoots when grown in 10% Hoaglands. Madson contained higher levels than Arco in shoots only. Uptake was linear for roots between 0.06 and 10 mM glycine but varied highly in shoots.Selecting varieties well adapted to competing for organic nitrogen could be an important means of maximizing productivity in organic and low input agricultural systems as plants gain more effective access to a wider pool of available nutrients in any given time.