1. Amur N, Semu E (2006) Fertility of rice-growing soils of Eastern Same district, Kilimanjaro region, Tanzania. I. Soil fertility status. UNISWA J Agric 14:52–61
2. Amuri N, Massawe F, Ernest N, Moyo S (2011) The linkages between innovations and indigenous knowledge in soil fertility management. CDE-ESAPP project extension flier
3. Branca G, McCarthy N, Lippe L, Jolejole MC (2011) Climate smart agriculture: a synthesis of empirical evidence of food security and mitigation benefits from improved cropland management. Mitigation of climate change in agriculture series 3, Food and Agriculture Organization of the United Nations (FAO), Rome, Dec, pp 1–36
4. Brye KR, Gbur EE, Miller DM (2004) Relationship among soil C and physiochemical properties of a Typic Albaqualf as affected by years under cultivation. Commun Soil Sci Plant Anal 35:177–192
5. Bumb B, Baanante C (1996) The role of fertilizer in sustaining food security and protecting the environment to 2020. 2020 Vision Discussion Paper 17. IFPRI, Washington, DC