Lime and phosphorus effects in maize (Zea mays L.) production.

摘要

The effectiveness of lime (L) and phosphorus (P) applications in acid soils may be influenced by crop species and cultivar grown. Incubation experiments were conducted in Nigeria on an Alfisol (sandy, pH 4.6) to evaluate the effects of liming (0, 1, 2, 3, 4 t Ca (OH)₂/ha), rock phosphate (RP), organo-mineral fertilizer (OMF) and single superphosphate (SSP) on pH and P availability. Extra early (ACR95TZ-ZEE-W₁) and early (ACR97TZE) maturing maize (Zea mays) cultivars were also grown in pots to investigate L and P effects in short and long terms. Treatments (control, 1 t Ca(OH)₂/ha, 88 mg P/kg of RP, OMF, L+RP, RP+OMF, L+OMF and L+OMF+RP) were replicated three times in CRD. Liming at 1.0 t/ha was optimum, raising soil pH and available P from 4.6 and 3.4 mg/kg to 6.2 and 8.36 mg/kg, respectively. L and P increased pH to 5.4-7.5, while the control was 4.5. P availability order was: RP+OMF > L > RP/OMF > L+RP+OMF > L+OMF > control. L+OMF (followed by OMF and RP+OMF) performed best, irrespective of cultivar. Residual P was highest with L+OMF and lowest in the control. L effectiveness was less than 100% with RP or OMF but higher with RP+OMF, especially in the long run. Under continuous maize cropping, RP and OMF sufficiently ameliorate acid soil infertility and may serve as an antidote against over liming.