A Cation exchange capacity refers to that C.E.C,in a certain pH value=7 ,the total number of moles of the exhangeable cations(K+,Na+,Ca+,Mg+,NH4+,H+,Al3+,etc.)contained in each kilogram of soil.
C.E.C is one of the most important index to measure the quality of humic acid,in other words,the higher the C.E.C,the better humic acid activity.For the same content of the products,the higher C.E.C,the better effect of water and fertilizer retention capacity,the more obvious effect it has on the plants.

A Leonardite is a kind of natural organic macromolecule polymer.It’s the high molecular uncertain polymer compound formed from the decomposition of plant residue and transformation of microorganism through tens of millions of years or even hundreds of millions of years,or a series of physical and chemical effects of the earth.It’s also an important source of humic acid raw materials.