References
- Anderson, JM and Ingram, JSI. (1993). Tropical Soil Biology and Fertility. A Handbook of Methods. CAB International, Wallingford, Oxon, UK.
- Jaetzold, R and Schmidt, H. (1983). Farm Management Handbook of Kenya. Vol. II. Ministry of Agriculture, Kenya.
- Makokha, S, Kimani, S, Mwangi, W, Verkuijl, H and Musembi, F. (1998). Determinants of manure and fertiliser use in Kiambu District, central Kenya. Paper presented at the 6th Eastern and Southern Africa Regional Maize Conference Maize Production Technology for the Future: Challenges and Opportunities 21–25 September, 1998, Addis Ababa, Ethiopia.