Wide variations were found from region to region in the percentage ash and of each of the individual mineral nutrient elements in the ash.
Wide variations were found in the cation-summation values. This is to be expected, since the environmental conditions under which the plants had been grown were very dissimilar.
Spinach was notably high in ash. Variations in K, Na, B, and Fe values were greatest in this plant. The K values varied between 10.05 and 3.31%, the Na values between 1.60 and 0.02%, the B values between 88 and 12 ppm, and the Fe values between 1584 and 19 ppm.8 Spinach appeared to be an accumulator of both Mo and Co.
Tomatoes showed the greatest variation in Ca, Mg, and Cu. The Ca values varied between 0.40 and 0.09%, the Mg values between 0.72 and 0.14%, and the Cu values between 46 and 0 ppm.
Snapbeans grown in Ohio, Indiana, Illinois, and Colorado were notably high in Mo. The average Mo value for the four east north-central states and Colorado was 3.9 ppm, in comparison with 0.4 ppm for the six coastal-plain states. The highest Mo value, 24.1 ppm, was found in a sample of Indiana cabbage.
Lettuce and spinach were two exceptions in the general trend of higher Mn values in the eastern states than in the east north-central states and Colorado. The explanation for this probably lies in the fact that eastern soils are usually well limed for these crops. Often they are overlimed. The lowest Mn value, 0.6 ppm, was found in a sample of lettuce from New Jersey, and the highest, 161 ppm, in a sample from Indiana.
Colorado vegetables, in comparison with those from the other nine states, were relatively high in Co, Mo, Cu, and Ca in the order indicated. They were moderately high in K, Mg, Fe, and B, in the order indicated. They were about average in P, relatively low in Mn, and very low in Na.
The K content of Colorado vegetables was not as high relatively as one might expect. The explanation for this is found in the fact that the soils of Colorado are relatively very high in Ca and Mg, as well as in K. It is important to note also that liberal applications of K, in the form of fertilizers and manures, are made to the land in the east and south in preparation for growing vegetables. This is in marked contrast to the very small rates of application of such materials in Colorado.