Potential of East African phosphate rock deposits in integrated nutrient management strategies

Anais da Academia Brasileira de Ciências

Bashir Jama²  Peter Van Straaten¹ 

[1],World Agroforestry CentreNairobi,Kenya

关键词: fertilizers;    maize;    improved fallows;    Tithonia;    East Africa;    fertilizantes;    milho;    mellhorando terras em pousio;    Tithonia;    África Oriental;   

DOI  :  10.1590/S0001-37652006000400012

来源: SciELO

【 摘 要 】

Phosphorus deficiency affects around 80% of the acid soils of western Kenya, but fertilizer use is limited due to high prices. This paper explores the potential of local phosphate rocks (PR) as a remedy within the context on an integrated soil fertility management approach. A promising phosphate rock is Minjingu PR (MPR, Tanzania), a sedimentary/biogenic deposit which contains about 13% total P and 3% neutral ammonium citrate (NAC) soluble P. On-farm trials in P-deficient soils in western Kenya demonstrate MPR to be as effective as triple superphosphate (TSP, 20% P) at equal P rates. The benefits are most pronounced with the integration of agroforestry technologies that improve soil fertility. Besides Minjingu PR, Busumbu PR from Uganda (BPR) is potentially another source of P. It is typical of the abundant but unreactive igneous PRs in eastern, central and southern Africa. Agronomic performance of BPR is poorer, though its lower cost and location near to P-deficient areas in western Kenya make it attractive in some situations. The policy implications of these findings are discussed further in the paper.

【 授权许可】

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