The Linear log quotient Mixture Model for the design space, there has been the analysis solution of D-optimal design given an a - optimal design by professor Guan Ying nan.

The optimal two-factor saturated D design was conducted to investigate effects of the active organic fertilizer made of grain stillage and other additives on rice yield.

The regression mathematical models for the yields of summermilletassociated with crop density, N and P fertilizers were established by using the optimal saturation D design.