Generally, protein content is negatively correlated to starch content. Thus, the slight increase in protein found in the 1996 samples would be expected to result in lower starch contents compared to the 1995 data. Indeed, starch content decreased 0.5 percentage points compared to the 1995 results. Starch ranges widened to 6.2 points compared to 4.9 points in 1996 and 1995, respectively. Significantly lower starch contents were evident in numerous samples.
Density is considered an indication of kernel hardness.
Overall, the composition data for the 1996 Indiana corn crop confirmed the variability in growing conditions experienced by farmers across the state last year. The results in Table 2 only give an indication of the composition values of corn across Indiana. Conditions during the growing season, hybrid selection, and soil fertility significantly affect intrinsic values such as protein, oil, starch, and density. Producers need to have their own samples analyzed to get more precise values. The Purdue University's Grain Quality Laboratory now offers composition analysis for whole corn, soybeans, and soybean meal.