Table 1.

Boundary conditions for the computational model; n is the unit normal to the relevant surface, ∂/∂n the normal derivative.

boundary	condition(s)	notes
Γyp	∂s/∂n = 0	symmetry
	∂T/∂n = 0	symmetry
Γyc	∂C/∂n = 0	symmetry
Γtop,side	C = C∞	controlled environment
Γsoil	D∂C/∂n = qsoil(Csat(T) − C)	water vapour flux due to evaporation from soil surface
Γin	s = s0	‘inlet’ saturation given for well-watered condition
	T = Ti	‘inlet’ temperature, which will be high for covered soil
Γ11,13,14,15, Γ21,23,24,25	ul · n = 0	zero normal liquid flux
	−K̂∂T/∂n = hplant/air(T∞ −T)	heat balance
	∂C/∂n = 0	zero normal vapour flux
Γ12,22	(ρlul) · n = E	liquid flux to evaporation site
	−K̂∂T/∂n = hplant/air(T∞ −T) + hvapE	heat balance with evaporation
	D∂C/∂n = (1/M)E	vapour flux driven by evaporation