Glycerin treated biodiesel

A composition soil amendment to control soil insects, the composition comprising: (a) an effective amount of a treated glycerin composition unpurified, wherein the glycerin composition unpurified is obtained as a byproduct of a reaction mixture for it produce biodiesel and crude glycerin composition is treated by: (i) adjusting the pH of the composition of glycerine unpurified 4.0 to 6.8 to obtain a neutralized composition; and (ii) separation of an insoluble precipitate of the composition; thereby obtaining the treated unpurified glycerin composition; and (b) an effective amount of a source of soluble nitrogen glycerin.