Maas–Hoffman Model
The Maas–Hoffman model is a mathematical tool to characterize the relation between crop production and soil salinity. It describes the crop response by a broken line of which the first part is horizontal and the second is sloping downward.Maas EV, Hoffman GJ, 1977. ''Crop salt tolerance-current assessment''. Journal of the Irrigation and Drainage Division, American Society of Civil Engineers 103: 115-134. The ''breakpoint'' (Pb) or ''threshold'' is also called ''tolerance'' because up to that point the yield is unaffected by the salinity, so the salt is tolerated, while at greater salinity values the crops are affected negatively and the yield goes down. Mathematics Mathematically the two lines are represented by the equations: : \left\{\begin{array}{l} Y=C, & XP_{\rm b} \end{array}\right. where ''Y''  is the crop production or yield, ''C''  is the maximum yield, ''X''  is the soil salinity, ''A''  is the slope (regression coefficient) ...
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