Fig. 2.

The effects of CO₂, P and water regime on dry weight (DW) of shoots (A) and roots in the 0–20, 20–40 and 40–60 cm soil layers (B), and water-use efficiency (WUE) (C) of field pea. Plants were exposed to ambient (aCO₂) or elevated CO₂ (eCO₂) treatments for 123 d in a P-deficient vertisol soil supplied with 15 (P15) or 60 mg P kg⁻¹ (P15) soil, and drought-stressed plants had water withheld until the soil reached the permanent wilting point in the last 3 weeks of the experiment. Columns are means of four replicates ± s.e. The vertical bars indicate the the LSD (P = 0.05).