Elements oxides as a source of errors in the gross chemical composition of soil and ways to eliminate the errors

Gross chemical composition of soils accepted in the form of oxides of express items and amount of oxides of macro elements equated with 100%. But the form of oxides is artificial and contrary to the actual mineralogy of soils. Errors in the content of the main macro elements nutrients of the solid phase of soils (oxygen) lead to errors in the content of all the rest of the macro elements. The oxygen content is greatly understated in the calcareous soils and clay soils of different genesis, silt soil fractions, as well as the Fe-Mn nodules. This leads to overestimation of the content of the rest of the macro elements. The oxygen content is heavily overstated in soils with natural sulphide and soils contaminated by sulphides: the sulphur content in the soil turns out to be heavily underestimated. The new technique of clarifying of the oxygen content take into account the loss on ignition, which leads to a decrease in all other macro elements in gross composition of soils.