The onion is a national crop; as widely though not quite as extensively grown as the potato. It is available as a money crop for the farm gardener.
Choice of Soil — Heavy, stiff clay land is to be avoided. Sand and gravel dry out too quickly. Stony land renders good culture difficult. The best soil for onions is a deep, rich, mellow loam. Soils which afford natural advantages for irrigation should not be overlooked, as the rainfall is often lacking when greatly needed.
Fertilizers — Onion culture demands high manuring. No amount of rotted stable manure is likely to be excessive. A ton per acre of high-grade, complete fertilizer is not too much, if moisture can be supplied. Hen manure is a good top dressing for onion-beds, furnishing the needed nitrogen. Nitrate of soda is a good source of nitrogen, if nitrogen must be purchased. The clovers and other leguminous crops yield the cheapest nitrogen. Wood ashes, kainit, etc., furnish potash. Either ground bone or acid phosphate will give the needed phosphoric acid. An analysis of the onion shows that it carries away fertility in just about the proportions furnished by stable manure.