- H.G. Meer van der (1)
- K. Nyombi (1)
- D.D. Onduru (1)
- P.J.M. Snijders (1)
- A.P. Wouters (1)
- J.Y.K. Zake (2)
Effects of cattle and manure management on the nutrient economy of mixed farms in East Africa: A scenario study
Snijders, P.J.M. ; Meer, H.G. van der; Onduru, D.D. ; Ebanyat, P. ; Ergano, K. ; Zake, J.Y.K. ; Wouters, A.P. ; Gachimbi, L.N. ; Keulen, H. van - \ 2013
African Journal of Agricultural Research 8 (2013)41. - ISSN 1991-637X - p. 5129 - 5148.
This paper explores effects of animal and manure management in a dairy unit on the nutrient economy of crop-livestock farms in East Africa. For this purpose, 8 cattle management scenarios have been developed based on farming systems in Mbeere, Kenya (extensive), Wakiso, Uganda (semi-intensive) and Kibichoi, Kenya (intensive). Three baseline scenarios represent present-day cattle management; five improved scenarios use the same dairy breeds but have improved nutrition, using younger grass, more legumes and moderate amounts of concentrates. These improvements strongly increase milk production per cow, but also N, P and K excretion in manure. The 8 cattle management scenarios are combined with 2 levels of manure management technology: a baseline technology, reflecting actual manure management and related losses of plant nutrients, and an improved technology with lower losses. Nutrient losses for each technology level have been derived from a thorough analysis of published information. This showed that current systems of collection and storage of the excreta of confined dairy cows are associated with large nutrient losses, in particular of N. These losses cause serious deficits on the N, P and K balances of the crop-livestock farms. Therefore, significant external N, P and K inputs and better manure management are required to sustain the production levels assumed and to avoid further soil fertility depletion in the region. The paper identifies several possibilities for this and concludes that there is a strong need for integral on-farm studies aiming at development of sustainable dairy production systems.
Efforts by Small-Scale Farmers to Maintain Soil Fertility and Their Impacts on Soil Properties, Luwero District, Uganda
Nyombi, K. ; Esser, K.B. ; Zake, J.Y.K. - \ 2006
Journal of Sustainable Agriculture 27 (2006)4. - ISSN 1044-0046 - p. 5 - 23.
Low soil fertility remains a major reason for rural poverty in sub-Saharan Africa. In light of the need to set priorities and formulate development policies, this study investigates efforts by farmers in central Uganda to maintain soil fertility, factors affecting their capacity to act and impacts on soil fertility parameters. Using questionnaire-based interviews and soil chemical analyses, information from 60 randomly selected farms was collected in four subcounties. Farmers use traditional conservation methods like legumes, crop rotation, cover crops, fallow and agroforestry in addition to applying manure, ash, mineral fertilizers and concoctions to improve soil fertility. Most farmers construct some soil bunds. Limited access to supplies, markets, credit and extension service, labor and organic materials are limitations to their ability to maintain soil fertility. Present application of fertility measures are clearly insufficient and are not reflected in soil fertility parameters