Agronomic Evaluation of Manure Ashes: Changes in Soil Phosphorus Fractions, Maize (Zea mays) Yield, and Phosphorus Uptake

ABSTRACT

In order to reduce bulkiness and concentrate its nutrients, manures were burnt to ashes, and the effect of manures and their ashes on soil phosphorus fractions and maize performance in laboratory incubation, screenhouse, and field experiments was evaluated. Treatments were control, dried poultry manure (DPM), poultry manure ash, dried cattle manure (DCM), cattle manure ash (CMA), dried goat manure, goat manure ash and NPK 15-15-15, each applied at 120 kg P ha⁻¹. Periodic data were taken from soil P fractions, maize yield, and P uptake. Results showed that manures and their ashes increased soil P fractions in incubation, screenhouse, and field experiments. Available P and Ca-P increased with application of DPM while CMA only increased labile P, Al-P, and Fe-P at later weeks. Dry matter yield and P uptake increased with the application of manures and ashes while available P was positively correlated with P uptake. The impact of manure ashes was comparable to manures, hence recommended for use as alternatives, thereby getting rid of the problems of manure bulkiness and offensive odors.

KEYWORDS:

• Agricultural waste management
• nutrient cycling
• soil nutrient pools

Acknowledgments

The authors wish to acknowledge the Soils of Forest Island in Africa (SOFIIA) project for its support in laboratory analyses. SOFIIA is a project sponsored by the Royal Society and the DFID of the UK. Opinions expressed and conclusions arrived at are those of the authors and are not necessarily to be attributed to the project.