50 Kg of ammonium sulphate (NH4)2SO4 and 30 Kg of urea CO(NH2)2 fertilizers were applied in two equal sizes of plots A and B to enrich their nitrogen content. Show by working which plot was more enriched with nitrogen. (N =14; S =32; O =16 ; C =12 ; H = 1) (KCSE 2011 paper question 19.)