Abstract:
This paper presents a study on nutrient dynamics of typical farms in arid and semi-arid areas in
Kenya, using the nutrient monitoring (NUTMON) research approach for assessing nutrient flows and
stocks and their effects on financial performance. Systematic collection of information on farm
management practices using structured questionnaires allowed quantification of material flows, with
emphasis on soil nutrients and cash flows. Based on data collected on inputs into the farm, outputs out
of the farm and internal nutrient flows, financial performance indicators are calculated at the farm
enterprise level, using the NUTMON toolbox. Participatory soil sampling and laboratory analysis
were carried out to determine total N, P, K and carbon stocks in the topsoil layer. Feedback to the
farmers was given on the soil analysis results, on the basis of graphs containing the average values for
each of the elements (N, P, K and carbon), to identify priorities in alleviating nutrient deficiencies and
determine appropriate integrated nutrient management strategies to address soil fertility problems.
This led to formulation of a research agenda to combat nutrient constraints during the experimental
design workshop. Farmers do associate poor crop yields with poor soil nutrient status and did recognize
the relevant symptoms, but not at the level of individual nutrients.
Averaged for all farms sampled, total nutrient balances, ie including inputs and outputs over the
farm gate, as well as exchange with the environment, such as biological (nitrogen) fixation, leaching
and/or volatilization, for N, P and K were negative. The losses in the total balances were mainly due to
leaching and erosion, processes that are not under direct control of the farmers. Average net farm
income was negative for the clusters operating entirely under rainfed conditions (Kionyweni,
Enkorika) and positive for the cluster where irrigation facilities are available (Matuu). In Matuu
more than 60% of the farm households have incomes above the rural poverty line, while 90% are below
that level in Enkorika.
