| dc.description.abstract | Soil acidity and phosphorus (P) deficiency are some of the major causes of low maize yields in Kenya.
This study determined the immediate and residual effects of lime and P fertilizer on soil pH, exchangeable
aluminium (Al), available P, maize grain yield, agronomic P use and P fertilizer recovery efficiencies on a
western Kenya acid soil. The treatments were: P fertilizer (0, 26 and 52 kg P ha−1 as triple super phosphate)
and lime (0, 2, 4 and 6 tons lime ha−1 ) applied once at the beginning of the study. A burnt liming material
with 92.5% calcium carbonate equivalent was used. Soil samples were analysed prior to and after treatment
application. The site had low soil pH–H2 O (4.9), available P (2.3 mg kg−1 ), total N (0.17%), high Al (2.0
cmol kg−1 exchangeable Al and 29% Al saturation). Lime reduced soil pH and exchangeable Al, leading
to increased soil available P. Lime at 2, 4 and 6 tons ha−1 maintained soil pH ≥ 5.5 for 2, 3 and 4 years,
respectively. The study observed that the recommended P fertilizer rate (26 kg P ha−1 ) for maize production
in Kenya was inadequate to raise soil available P to the critical level (≥10 mg P kg−1 soil bicarbonate
extractable P) required for healthy maize growth. To maintain soil available P at the critical level where 52
kg P ha−1 and combined 52 kg P ha−1 + 4 tons lime ha−1 were applied, it would be necessary to reapply
the same P fertilizer rate after every one and two cropping seasons, respectively. The 4-year mean grain
yield increments were 0.17, 0.34, 0.50, 0.58 and 1.17 tons ha−1 due to 2, 4, 6 tons lime ha−1 , 26 kg P
and 52 kg P ha−1 , respectively. Both agronomic P use and P fertilizer recovery efficiencies increased with
increasing rates of lime and decreased with increasing rates of P fertilizer. Therefore, combined applications
of both lime and P fertilizer are important for enhancing maize production on P-deficient acid soils in
western Kenya. | en_US |
