Back J. F. Prinsloo and H. J. Schoonbee
Aquaculture Research Unit, University of the North, P/Bag X1106, Sovenga, 0727, South Africa
Full Paper (PDF File: 322KB)
Abstract
Integrated aquaculture-agriculture production systems were developed primarily
for sustainable food production in rural areas of South Africa. The problem
of environmental pollution was addressed by utilizing the nutrients in
the agricultural waste products to fertilize the fish ponds, thus stimulating
pond productivity and releasing nutrients such as nitrogen and phosphorus
into irrigation water for vegetable crop production. Due to problems encountered
with soil quality as a result of the build-up of nutrients due to chemical
fertilizers and the excessive use of pesticides, it was decided to implement
EM technology to restore the organic and micro-biological balances of the
cultivated lands. Three vegetable crops, namely cabbage, spinach and lettuce,
were cultivated under different irrigation systems, using EM, organic compost
and inorganic chemical fertilizing programmes. After the first application
of EM Bokashi, significant improvements in vegetable yields were recorded.
EM treated plots proved to be superior in the yields of cabbage and lettuce
clearly exceeding the agricultural average for South Africa. In the case
of spinach, EM treated plots under drip irrigation proved to be the most
productive. Application of irrigation water as well as soil quality, appeared
to be two factors that must be considered when acertaining the amount of
EM to be applied to further improve yields following organic farming. Recommendations
are made to evaluate the health status of EM treated soils.