Plant Analysis
Plant analysis is a more direct indicator of plant nutrition than are soil tests. However, care must be taken in interpreting plant analysis values because of environmental and cultural factors that may interfere. If a deficiency is suspected, collect whole plant samples if the corn is less than 12 inches high, or the uppermost mature leaf if the plant is more than 12 inches high but before the tassel stage. If the tassel has emerged, collect the ear leaf