Many chemical fertilizers are commonly used to improve soil fertility and productivity. Urea, TSP, MP, Gypsum, Borax, Ammonium nitrate etc. are used familiarly all over the world. Though these can improve the fertility of soil for the time being but in the long run they will become toxic to the soil and make hamper to the microorganisms. Now the question is which chemical is more hazardous to the microorganisms?