|Better Farming Series 19 - Market Gardening (FAO - INADES, 1977, 56 p.)|
75. Onions develop the end of their stems underground. This part of the stem which fattens in the earth is called the bulb.
The bulb grows quickly and becomes large if the soil is light, not too moist, rich in humus and free from weeds.
76. The soil must not be too moist
If the soil is very moist, the bulb may rot. In a well- tilled soil, the water goes down deep and air can get in.
So till the soil deeply.
77. The soil must be rich in humus.
It is best to grow onions after salad plants. Salad plants do not use all the mineral salts in the soil. Onions use up the salts that remain from the manure you put down for the first crop.
Apply fertilizers. Onions need above all potassium and phosphorus. Sulfur is often very useful too.
Ask the supplier or the extension services how much fertilizer to apply.
Do not apply too much nitrogen, otherwise the leaves will develop more than the bulbs.
Never grow two crops of onions one after the other, because of diseases.