Table I.

Total shoot N concentration, shoot C to N ratio, photosynthesis, transpiration, and stomatal conductance of 11-week-old L. perenne and B. erectus

Grass SpeciesN TreatmentTotal NC to N RatioPhotosynthesisTranspirationStomatal Conductance
% in dry matter μmol m−2 s−1 mmol m−2 s−1
L. perenne KNO3 2.2 ± 0.118.8 ± 1.12.39 ± 0.100.48 ± 0.0121.1 ± 0.5
NH4HCO3 3.1 ± 0.214.4 ± 1.22.90 ± 0.200.55 ± 0.0124.0 ± 0.4
NH4HCO3 × 24.9 ± 0.28.9 ± 0.42.58 ± 0.350.59 ± 0.1025.8 ± 4.4
B. erectus KNO3 4.9 ± 0.38.1 ± 0.56.18 ± 1.041.59 ± 0.0469.6 ± 1.9
NH4HCO3 4.4 ± 0.310.2 ± 1.34.68 ± 1.271.22 ± 0.0756.4 ± 3.4
NH4HCO3 × 26.0 ± 0.27.4 ± 0.26.36 ± 0.751.53 ± 0.1166.9 ± 4.7

Plants were grown for 6 weeks with different N supplies (3 mm KNO3, 3 mmNH4HCO3, or 6 mmNH4HCO3) in the nutrient solution. Values are means ± se of three replicate samples.