
Figure 2. Typical Spanish soil mix 'Enarenado', which is used as a base in 90% of the vegetable greenhouses in the Almeria region. Approximately 12 inches of a new soil, which is partially clay, is placed on top of the original soil in the region, then an inch of manure then 4 inches of sandy gravel is placed on top of the manure. Methyl bromide is not used for fumigation and the 'manufactured' soil can be used for several years without major pest problems.