Yield and nutrient uptake by maize as influenced by phosphorus and zinc application

Bulk soil samples from a long term (45 years) experiment were collected with three treatments (100% N, 50% NPK and 100% NPK) to represent different soil fertility levels for green house study using maize as test crop. To each soil, combinations of 4 levels of P (0, 30, 60 and 120 mg P kg⁻¹) and Zn (0, 6.25, 12.5, 25 mg Zn kg⁻¹) were applied in pots containing 4 kg soil. The effects of different levels of P and Zn were examined on dry matter yield, P and Zn concentrations and their uptake at 45 days after sowing. Soil collected from 100% N plots had the highest dry matter yield and P concentration but the lowest Zn concentration in maize plants. Soil from 100% NPK plots had the highest Zn concentration but lowest dry matter yield. Phosphorus application increased dry matter yield, whereas Zn had minimal effect on dry matter yield. Significant effect of P on Zn concentration was observed, whereas Zn had no effect on P concentration in maize plants.