NUTRIENT MONITORING (NUTMON) RECONNAISANIE SURVEY IN THE SEMI-ARID AREAS OF EASTERN KENYA.

Abstract

There is a problem of low yields due to poor soil fertility in the agro-ecological zones (AEZ) IV and V in Eastern Kenya (Simpson et al., 1992). Most of the soils are sandy with low organic matter content. In particular, nitrogen and phosphorus deficiency is widespread in maize crops that are grown continuously on cultivated land without nutrient replenishment (Okalebo et al. 1992). Normal farming practice in the region involves little return of crop residues. Farm resources do not allow purchases of fertilizers (Rukandema 1984), and manure use is limited by its poor quality and unavailability (Probert et al., 1992). Continuous cultivation without replenishment of plant nutrients must in time result in productivity declining to low levels. In order to design appropriate and integrated nutrient management strategies, the nutrient flows at farm level need to be clearly understood. A nutrient balance study was conducted in three wetter districts in Kenya (Van de Bosch et al., 1997) and partial balances of +35 kgN, +15 kgP and +51 kg K ha¹ yr¹ were achieved. Such studies have not been conducted in the semi-arid areas of Eastern Kenya. A nutrient monitoring reconnaissance survey was therefore conducted in Machakos, Kitui, Mwingi, Makueni and Kajiado district in order to familiarise the researchers with the land use systems, sensitise the stakeholders on the need to monitor nutrient flows and assess the farmers knowledge on the concept of nutrient flow at farm level.