Homogeneity tests Regarding test methods for degree of mixing the standardisation of fertilizers is a special case. Homogeneity tests could be used for different purposes: 1) Identifying bulk blends as such 2) Control of degree of mixing 3) Comparison of mixers 4) Optimisation of mixing time 5) Check of blending equipment Test og the degree of mixing In mixing test, the statistical variation of the composition is used as a measure for the degree of mixing, expressed in some kind of index. Indirect methods Aside from mixing tests, in the practice of fertilizer blending, indirect methods are used for assessing the physical compatibility of the granular compon