Soil Silica and Phosphorus Response by Maize In Acid East African Soils

Abstract

Birch found significant and inverse relationships between percentage responses to phosphorus fertilizer and the amount of water or citric soluble silica in acid East African soils [1], for wheat and grassland crops Researches reported by other workers [e.g. 1, 2, 3, 4, 5, 6] show that there exists a dynamic interaction Between silicon, iron and aluminium with phosphate ions in the soil, leading to a variable degree of fixation; the extent and reversibility of this interaction is pH dependent. It is generally held that a high degree of phosphate ion fixation in acid soils by iron and/ or aluminium tends to mask expected crop responses to applied phosphorus. More recently, work has been published which suggests that the ph03- phate ion fixation may need to be saturated by fertilizer application to a lesser or greater degree, before crop responses can be predicted or observed with accuracy [7, 8].