Vermiculture in Egypt: - FAO - Regional Office for the Near East and

which humic acids could affect plant growth. There is a further alternative explanation
for the hormone-like mode of action of humic acids in these experiments. In our
laboratory, we have extracted plant growth regulators such as indole acetic acid,
gibberellins and cytokinins from vermicomposts in aqueous solution and
demonstrated that these can have significant effects on plant growth. Such substances
may be relatively transient in soils. However, there seems a strong possibility that
such plant growth regulators which are relatively transient may become adsorbed on
to humates and act in conjunction with them to influence plant growth (Atiyeh et al.,
2002).
Vermicompost has been promoted as a viable alternative container media component
for the horticulture industry. The addition of vermicompost in media mixes of 10%
and 20% volume had positive effects on plant growth. The greatest growth
enhancement was on seedlings during the plug stage of the bedding plant crop cycle.
Growth increases up to 40% were observed in dry shoot tissue and leaf area of
marigold, tomato and green pepper. The increased vigor exhibited was also
maintained when the seedling plugs were transplanted into larger containers with
standard commercial potting substrates without vermicompost. Additionally, there
were benefits apparently resulting from the nutritional content of the vermicompost.
All of the plugs were produced without the input of additional fertilization. The
potential exists for growers to use vermicompost-amended commercial potting
substrates during the plug production stage without the use of additional fertilizer
(Bachman and Metzger, 2008).
5.4. Potentiality of vermicompost as a source of fertilizer in Egypt
Considering urban wastes as mentioned in the previous chapter for the year 2005
ranged from 15 to 16 million tons, compostable matter in the wastes as 50-60% and
average collection efficiency as 70%. Egypt has an estimated potential of producing
from urban wastes about 1.99 million tons of compost each year containing about
21,000 ton N, 5,000 ton P, and 10,640 ton K (Table 5.2). Inappropriate solid waste
management and production of poor quality of composts are main constraint in
exploiting such large amount plant nutrients for increasing crop productivity.
On the other hand, agricultural wastes in Egypt could produce almost four times
compost material compared to urban wastes, assuming that 100% of it is organic
material and all of it is accessible to the grower. There are other advantages of this
waste, which are the availability of space and directly linked to the farm. This
minimizes the need of collection and transportation. The amounts of N, P and K that
could be produced from agricultural wastes are almost four folds of that of the urban
wastes.
From both sources, the total composted material is almost 10 million tons, containing
about 10 thousand tons of nitrogen, 20 thousand tons of phosphorus, and 41 thousand
tons of potassium. Nitrogen fertilizer obtained from organic wastes could save up to
5.9% of that consumed in 2008; while more than 10% of phosphorus fertilizers
consumed in 2008 could be saved.
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