Influence of phosphorus fertilizer placement and fertilization rate on maize nutrition
1978
Fox, R.L. | Kang, B.T.
An experiment was conducted on a sandy loam Alagba soil in southern Nigeria to obtain information on the effectiveness of methods of applying P fertilizers on soils of the humid tropics. Phosphorus rates ranging from no phosphate applied to 256 kg P per hectare applied, and percentage of the soil volume fertilized, ranging from banding to 100 percent incorporation in the surface (0–15 cm) soil volume, were tested in factorial combinations using a continuous function experimental design. Response to P fertilization was greatest during early growth and decreased with advanced maturity. External P requirements at 3, 6, and 9 weeks of growth were estimated at about 6, 0.02, and 0.001 μg P/ml, respectively. A rather low soil solution concentration of 0.01 μg P/ml was associated with 95 percent of maximum grain yield, which may be related to the low yield level realized. Advantages of localized P placement were observed only at suboptimal P rates. With an adequate rate of fertilization, the best results were obtained from incorporating P in the entire cultivated soil volume. This study did not support the idea sometimes put forward that major economies in fertilizer use can be achieved as a result of localized placement of phosphate fertilizer.
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