Fig. 1. Irrigation schedule for each treatment. The dashed line represents the application of 44 kg P ha^-1 as single superphosphate. E_p - R = accumulated U.S. Class A pan evaporation minus rainfall. For treatments, _nF_m is the fertilizer application, where _n is the nominal soil water deficit as described by E_p - R at fertilizer application, and _m is the nominal change in soil water content between fertilizer application and the subsequent irrigation and is described by the additional accumulated E_p - R. I_p is the irrigation that established E_p - R at fertilizer application. I₁ is the first irrigation following fertilizer application. I₂ and I₃ are the second and third irrigations following fertilizer application. represents 11.4 mm of rainfall that fell 4 d after fertilizer application.