Maize and wheat N-uptake (average over stages of development) in response to the application of biochars with and without N fertilizer under greenhouse conditions.

<p>Treatments included i.e. T₁ = control, T₂ = urea N (UN) at 200 mg kg^-1, T₃ = urea N (UN) at 100 mg kg^-1, T₄ = white clover residue biochar (WCRB) at 30 t ha^-1, T₅ = poultry manure biochar (PMB) at 30 t ha^-1, T₆ = WCRB+PMB (50:50 w/w), T₇ = UN+WCRB (50:50 w/w), T₈ = UN+PMB (50:50 w/w), and T₉ = UN+WCRB+PMB (50:25:25 w/w). The vertical lines on each bar represent the least significant difference (LSD at <i>P</i> ≤ 0.05) among different treatments for each trait while the letters on each bar highlight the statistical differences among the treatments for the traits studied.