A QUANTITATIVE APPROACH TO PREDICT ... - SuSanA

after the enhancement of the N is named comlizer (excreta based compost-fertilizer
mixture). 168 When the fertilizers are produced, they are supplied to the farmers in the
peri-urban and in the urban area for farming. Some crops produced with the fertilizer
are tomatoes, sweet pepper, lettuce, cabbage, spring onion and carrot. 169 The application
of compost which is an organic fertilizer has been argued to have more potentials of
increasing plant yield as compared to inorganic fertilizers because of its “organic
matter” effect which makes it similar to the soil. 170 It is noted to suppress the
development of nematode which eat the roots of plants and prevent diseases which
makes it unnecessary to use pesticides in farming. It as well helps improve the quality
of clayey and sandy soil. Table3 shows the impact of compost on these types of soil.
Table 3:
Impact of composting on sandy and clayey soil
Impact on sandy soil
Water content is increased
Water retention is increased
Aggregation of soil particles is enhanced
Erosion is reduced
Impact on clayey soil
Aeration if soil is increased
Soil is permanently increased
Potential crushing of soil surface is
reduced
Compaction is reduced
Source: Strauss, Martin et al, 2003, p. 22
To attain these benefits, it is better if wastes from all sources before their application to
farms pass through composting processes so as to minimise their negative effects on the
soil, reduce plant and animal pathogens and to increase their soil fertility functions. The
raw application of organic waste without composting may have some negative effect
because of initial variations that may exist between the organic wastes and the soil. The
study of Hernández supports this argument as it came to the conclusion that because of
the humified nature of compost, it helps the soil than direct application of sludge. 171
Nkansa-Boadu realised in his study that some farmers in the Manya Krobo district of
168 Adamtey, Noah, et al 2009, pp.17 and 2430
169 Olofunke, Cofie and Kone, Doulaye, 2008, pp. 1-2
170 Senesi, 1989, p.523-526
171 Hernández, et al 2006, p. 1376
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