| Sumario: | An essential aspect for smallholder crop-livestock farmers in sub-Saharan Africa is
productive soils in order to maintain animal and crop productivity. Often, these systems
are heavily dependent on local resources for their input and as a result, manure forms
an important by-product to serve as fertiliser for their land. As part of the CGIAR
Research Program on Climate Change, Agriculture and Food Security (CCAFS), research
on manure management in smallholder farmers in Nyando, western Kenya was done.
The aim of this research was to assess manure management practices and current
nutrient losses that occur through the manure management cycle. Based on these
results, novel management activities were described that could improve current manure
management and reduce nutrient losses. A questionnaire was used to acquire data on
farm characteristics, manure management and farmers’ perceptions of 20 farms in the
Nyando district. Fresh and stored manure samples were taken on-farm and analysed on
nutrient content. Based on these results, nutrient losses between fresh and stored
manure were calculated. The FARMSIM simulation model was used to calculate herd
dynamics and production, especially production of manure. Results showed that
between fresh and stored manure, dry matter loss was on average 75% and carbon,
nitrogen and phosphorus showed an average loss of 80, 74 and 45%, respectively. On
average, 82 kg N ha-1 year-1 was produced, whereas 42 kg N ha-1 year-1 was collected and
only 17 kg N ha-1 year-1 was applied on farm.
The results indicated that between manure excretion, collection and application large
losses occur. Particularly manure collection and method of storage (i.e. manure stored
on a heap or in a put, and uncovered or covered with a shed or tree) play an important
role. Furthermore, current manure management practices do not provide the farm with
sufficient amounts of nutrients needed for a stable crop production. Improvement of
manure management practices could reduce nutrient losses and increase overall
manure quality. Novel practices include more frequent collection of manure, decreasing
the period of storage, covering the manure with a plastic sheet and altering the storage
unit in order to reduce nutrient losses through leaching and evaporation.
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