Abstract: In this study, a brief study on yield production is presented in various mathematical methods just, so, five modeling and the most significant factors affecting on crop yield growth are studied. The multiple linear regression is applied from reference studies to predict the crop yield. Richard's equation by fully implicit finite difference scheme is presented to prophesy volumetric water content in crop yield growth and the growth relationship between crop yield Y and the nitrogen N is explained. Also, the mathematical model for crop yield production is described in four main stages. The model of a crop production is converted into a system of equations that are solved numerically. Moreover, the empirical Blaney-Criddle equation for water yield is formulated at different crops such as rice, cotton and wheat.