Definition of fertilizer:
humus, nitrogen, mulch, phosphorus, dung, bone meal, peat moss, commercial fertilizer, chemical fertilizer, feed, kelp, guano, ammonium sulfate, potash, fertile, fertilise, legumes, phosphate, fertiliser, litter, plant food, sphagnum, seaweed, superphosphate, top dressing, nitric nitrogen, desertification, compost, fertilization, fertility, bone dust, crushed limestone, organic fertilizer, fertilize, ammonic nitrogen.
- "Dry-Farming", John A. Widtsoe.
- "State of the Union Addresses of Calvin Coolidge", Calvin Coolidge.
- "Complete State of the Union Addresses from 1790 to the Present", Various.