VEGETABLES - World Food: Production and Use - page 136

In regions where rainfall is insufficient for vegetable production, irrigation is essen-
tial. In some locations where rainfall is sufficient but does not come at times essential for
vegetable production, irrigation is practiced. Vegetables are generally considered high
value crops and so irrigation may be practiced even when it is not deemed necessary
for other crops. Also more expensive irrigation methods, such as drip irrigation, may
be used both to promote better vegetable production and to conserve water.
Although specific soil types are better suited to production of a particular veg-
etable, it is not true that soil type absolutely determines what can be grown. Typically,
all types of vegetables grow well in most soils, as long as they have adequate water,
nutrients, and temperature and are not compacted. Clayey soils hold nutrients well
but are hard to work and are easily compacted and so are not favored by farmers,
although they may be highly productive. Loamy soils, that is, sandy loams, clay
loams, and silt loams (Chapter 9), are preferred agricultural soils throughout the
world. Sandy and organic soils are well suited for all types of root vegetables
because they allow easy development of the root portion of the vegetable. However,
they do not hold water or nutrients well and so require addition of both in lager quan-
tities than other soils.
Organic soils are well suited and very productive when used for vegetable pro-
duction. However, because of their unique characteristics, such as nutrient and water-
holding capacities, must be managed differently from mineral soils.
People all over the world cultivate vegetables in small family gardens or in areas
smaller than those used for field crops. Cultivation of these gardens is extremely varied.
The soil may be worked with Maddox, shovel, rototiller, or other tool. The ground may
be left flat, hilled, or worked to produce ridges on which seed is planted; see Figure 4.1.
Another popular method is called raised beds where boards, 5 cm by 15 cm, are placed
on edge to form a “box” 90 cm wide and 300 cm long is made and filled with soil, as
shown in Figure 4.6. Organic matter, mulch, and manure can be added and worked into
Figure 4.6. Raised beds, “boxes,” surrounded by planks. Center bed is planted to broccoli.
Plastic hoops are used to hold plastic covers in cold weather.