Competing use of organic resources, village-level interactions between farm types and climate variability in a communal area of NE Zimbabwe
In communal areas of NE Zimbabwe, feed resources are collectively managed, with herds grazing on grasslands during the rainy season and mainly on crop residues during the dry season, which creates interactions between farmers and competition for organic resources. Addition of crop residues or animal manure is needed to sustain agricultural production on inherently poor soils. Objectives of this study were to assess the effect of village-level interactions on carbon and nutrient flows, and to explore their impact on the long-term productivity of different farm types under climate variability. Crop and cattle management data collected in Murewa Communal area, NE Zimbabwe was used together with a dynamic farm-scale simulation model (NUANCES-FARMSIM) to simulate village-level interactions. Simulations showed that grasslands support most cattle feed intake (c. 75%), and that crop residues produced by non-cattle farmers sustain about 30% of the dry season feed intake. Removal of crop residues (0.3-0.4Â tÂ CÂ ha-1Â yr-1) from fields of non-cattle farmers resulted in a long-term decrease in crop yields. No-access to crop residues of non-cattle farmers increased soil C modestly and improved yields in the long-term, but not enough to meet household energy requirements. Harvest of grain and removal of most crop residues by grazing cattle caused a long-term decline in soil C stocks for all farm types. The smallest decrease (-0.5Â tÂ CÂ ha-1) was observed for most fertile fields of cattle farmers, who manure their fields. Cattle farmers needed to access 4-10Â ha of grassland to apply 3Â t of manure ha-1Â yr-1. Rainfall variability intensifies crop-livestock interactions increasing competition for biomass to feed livestock (short-term effect) or to rehabilitate soils (long-term effect). Prolonged dry seasons and low availability of crop residues may lead to cattle losses, with negative impact in turn on availability of draught power, affecting area under cultivation in consecutive seasons until farmers re-stock. Increasing mineral fertiliser use concurrently with keeping crop residues in fertile fields and allocating manure to poor fields appears to be a promising strategy to boost crop and cattle productivity at village level. The likelihood of this scenario being implemented depends on availability of fertilisers and decision of farmers to invest in rehabilitating soils to obtain benefits in the long-term. Adaptation options cannot be blind to what occurs beyond field and farm level, because otherwise recommendations from research and development do not fit the local conditions and farmers tend to ignore them.
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Dekker, Marleen, 2004. "Sustainability and Resourcefulness: Support Networks During Periods of Stress," World Development, Elsevier, vol. 32(10), pages 1735-1751, October.
- van Wijk, Mark T. & Tittonell, Pablo & Rufino, Mariana C. & Herrero, Mario & Pacini, Cesare & Ridder, Nico de & Giller, Ken E., 2009. "Identifying key entry-points for strategic management of smallholder farming systems in sub-Saharan Africa using the dynamic farm-scale simulation model NUANCES-FARMSIM," Agricultural Systems, Elsevier, vol. 102(1-3), pages 89-101, October.
- Powell, J. M. & Fernandez-Rivera, S. & Hiernaux, P. & Turner, M. D., 1996. "Nutrient cycling in integrated rangeland/cropland systems of the Sahel," Agricultural Systems, Elsevier, vol. 52(2-3), pages 143-170.
- Manlay, Raphael J. & Ickowicz, Alexandre & Masse, Dominique & Feller, Christian & Richard, Didier, 2004. "Spatial carbon, nitrogen and phosphorus budget in a village of the West African savanna--II. Element flows and functioning of a mixed-farming system," Agricultural Systems, Elsevier, vol. 79(1), pages 83-107, January.
- Giller, Ken E. & Rowe, Ed C. & de Ridder, Nico & van Keulen, Herman, 2006. "Resource use dynamics and interactions in the tropics: Scaling up in space and time," Agricultural Systems, Elsevier, vol. 88(1), pages 8-27, April.
- Sandford, Stephen & Scoones, Ian, 2006. "Opportunistic and conservative pastoral strategies: Some economic arguments," Ecological Economics, Elsevier, vol. 58(1), pages 1-16, June.
- Tschirley, David L. & Jayne, T.S., 2010. "Exploring the Logic Behind Southern Africa's Food Crises," World Development, Elsevier, vol. 38(1), pages 76-87, January.
When requesting a correction, please mention this item's handle: RePEc:eee:agisys:v:104:y:2011:i:2:p:175-190. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Shamier, Wendy)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.