The Mineral Resources Unit of UNU-INRA initiated a project to convert local phosphate rocks into more readily soluble forms through acidulation with mineral acids; the resulting product is known as partially acidulated phosphate rock.

In combination with low-cost, locally produced agricultural lime, partially acidulated phosphate rock is very effective on the highly acidic soils of northwestern Zambia.

Wherever they have appeared, they have brought with them death and desolation, undermined efforts at economic and social development and compromised attempts at conflict resolution that have been the result of implementing acidulously negotiated agreements.

In collaboration with scientists in the School of Agricultural Sciences of the University of Zambia, the partially acidulated phosphate rock produced by the Mineral Resources Unit from Chilembwe phosphate rock has been field tested on crops.

Results show that, when applied to maize, sunflowers, soya beans and groundnuts, partially acidulated phosphate rock is as effective as imported mono-ammonium phosphate and is more suitable for long-term improvement of the phosphorus capital of the soils because it acts as a slow-release fertilizer with longer-lasting residual effects.