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Figure 3. Total Nproduced by various types of biomass.
Means followed by the same letter are not significantly different.
Conclusion and Recommendations
The major contribution of the green manure crops
evaluated was found to be their supply of nitrogen
to the subsequent crop. For small-scale producers,
sunnhemp species were likely to supply adequate
nitrogen for cereal crops. hI the case of velvet bean
varieties, half of the total N required by cereal crops
would have to be supplemented from organic and
mineral sources. The amount of P contained in the
biomass was insignificant for normal plant growth.
External sources of P have to be added to crops at
the recommended rates.
Future Research Needs
There is need to quantify the nu.trient contribution
to the soil by the green manure crops, i.e. evaluate
the below ground effect of the green manure fallows.
Acknowledgements
The authors would like to acknowledge the Land
Management and Conservation Farming (SCAFE)
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Figure 4. Total Pproduced by various types of biomass.
Means followed by the same letter are not significantly different.
SIDA/MAFF Project for the funding that made this
study possible. Great thanks are also expressed to
the Crop Science Department of the University of
Zambia, for the support rendered during the study.
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