Effect of soil amendments on availability of soil phosphorus and uptake by maize in Vihiga County, western Kenya

Abstract

The combined use of organic inputs and fertilizers as promoted via Integrated Soil

Fertility Management (ISFM) approach may have a significant effect on bioavailability

of phosphorus (P) and enhance its uptake by crops. A field study was

conducted to determine the effects of combined use of lime, NPK fertilizer, farmyard

manure (FYM) and Zinc (Zn) on short-term changes in available soil P. This was

followed by determination of P uptake in the stover and the maize grain. Thus, four

field experiments were established in four sites. The

treatments weree (i) an absolute control, (ii) NPK (100 kg N ha-1, 30 kg P ha-1

, 42 kg K ha-1 ), (iii) NPK + FYM (2 t ha-1), (iv) NPK + FYM (2 t ha-1) + Lime (2 t

ha-1) + Zn (3 kg ha-1), (v) NPK + FYM (3 t ha-1), (vi) NPK + FYM (4 t ha-1) and (vii)

NPK + Lime (2 t ha-1) + Zn (3 kg ha-1). Each of these treatments were replicated three

times and randomly allocated within each replicate. Soils were sampled at 0, 42, 86

and at 120 days after planting and analyzed for available P content.

Combined use of NPK , FYM, lime and Zn gave significantly

larger (P<0.05) available P levels after 42, 86 and 120 Days after planting

relative to the control. For maize ear leaf, the largest total P content were observed

in all treatments containing FYM. In the maize grain,  the treatment (iv) resulted

in the largest P content.