Assessing the potential benefits of organic and mineral fertiliser combinations on maize and legume productivity under smallholder management in Zimbabwe
Date
2009
Journal Title
Journal ISSN
Volume Title
Publisher
African Crop Science Society
Abstract
Low inherent soil fertility status coupled with little or no external nutrient inputs have contributed to rapid soil nutrient
depletion and low maize yields that rarely exceed 1 t ha-1 in Southern Africa, threatening household food security. A study was
initiated in the 2008/09 season to determine the effects of combined application of basal P- containing fertilisers and locally available
organic nutrient sources on productivity of cowpea and soybean on smallholder farms. An evaluation of how cowpea productivity
can be influenced by farmer management and resource endowment, in a market oriented production system was also done. Vigna
unguiculata, Glycine max, Crotalaria juncea and selected indigenous legumes of the genera Crotalaria, Tephrosia and Indigofera
were grown using combinations of traditional Compound D (N: 7%, P2O5: 14%, K2O: 7%) and a PKS (P2O5: 32%, K2O: 16%, S: 5%)
basal fertiliser formulation, with either cattle manure or leaf litter. Legume biomass sampled at 50% flowering was in the range of 0.8
– 3.9 t ha-1, the maximum being for basal D combined with cattle manure. There were no significant differences between treatments
at a site which had < 0.5% organic carbon. Cowpea grain yield from resource endowed farmers was significantly different to the other
farmer resource groups, but averaged only 0.9 t ha-1. At the site which became waterlogged sunnhemp contributed only 9 kg N ha-1,
but at other sites the green manure species contributed N ranging from 54 – 133 kg ha-1. Overall, legume productivity and N
contribution increased with P application and the maximum was recorded when nutrient sources where combined, despite the
superior performance of D combined with either manure or litter, over PKS combinations. We concluded that grain legume yields can
hardly exceed 1 t ha-1, without external nutrients, on sandy soils with low organic matter thus combining locally available resources
and mineral P- fertilisers can be a better option to boost productivity of N2-fixing legumes.
Description
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Conference Paper
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Keywords
COMMUNITY PARTNERSHIPS, CROP PRODUCTIVITY, LEGUMES, NUTRIENT DEPLETED FIELDS, CROP SCIENCE, FERTILIZERS, MAIZE AND LEGUME PRODUCTIVITY, ZIMBABWE, COWPEAS, SOYBEANS
Citation
Kanonge, G., Nezomba, H., Chikowo, R., Mtambanengwe, F., & Mapfumo, P. (2009). Assessing the potential benefits of organic and mineral fertiliser combinations on maize and legume productivity under smallholder management in Zimbabwe. Proceedings from the African Crop Science Conference. African Crop Science Society, 9: 63-70.