These fertilizer experiments in the greenhouse and field gave the following results:
1. The 2-12-2 and 0-12-2 had a greater effect on the development of both the primary and secondary roots of corn than the 0-12-0.
2. Germination and root growth of corn were retarded when the fertilizers were applied in contact with the seed.
3. The desirable effects of fertilizers on the early growth, maturity and yield of corn appeared to be in proportion to the development of the roots of the plant.
4. The greatest development of both the primary and secondary roots was secured when the fertilizers were applied in the hill thoroly mixed with the soil in an area large enough to prevent any retardation of germination.
5. In greenhouse experiments the 2-12-2 and 0-12-2 applied in the hill mixed with the soil decreased the production of nitrates and lowered the nitrifying power of the soil for two weeks after the fertilizers were applied.
6. The retardation of germination of corn was not due entirely to the osmotic pressure of the salt solution. The elongation of cells and the rate of cell division was retarded by certain fertilizers independently of the osmotic influence.
Smith, Frederick B.
"Some effects of method of application of fertilizers on corn and soils,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 8
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol8/iss104/1