Compute the gypsum required to reduce esp

Question

A laboratory analysis showed the following results:

            CEC = 20 meq/100g                       soil solution Ca = 6 meq/1

            CaCO₃ = 0.2%                                soil solution Mg = 2 meq/1

            pH = 8.6                                          soil solution Na = 36 meq/1

            EC = 5.0 mmhos/cm

a. Calculate SAR, ESR, and ESP

b. Calculate the Gypsum (lbs/afs) required to reduce ESP to 5%.

c.  Does the soil contain enough lime to reduce ESP to 5% if S were used instead of gypsum?  How much S (lbs/afs)  is required to reduce ESP?