Effect of phosphorus and nitrogen sources on essential nutrient concentration and uptake by maize (Zea mays L.) during early growth and development

摘要

In South Africa, maize is often produced on highly weathered soils with low organic matter contents. These soils are unable to supply sufficient nitrogen (N) and phosphorus (P) for sustainable maize production, resulting in the use of fertiliser sources containing either N or P. In some instances, however, the efficiency of these sources may be questioned. In a glasshouse pot experiment, young maize aerial plant material was analysed to evaluate the effect of band-applied N sources, P sources and P application rates on the quantitative nutrient concentration, as well as uptake of several nutrients. With the exception of potassium uptake, all parameters were significantly affected by the main effects only. Nutrient concentration measurements were inconsistent for N sources. However, total uptake proved to be more efficient with the application of limestone ammonium nitrate compared with that of urea. Both nutrient concentration and uptake were greater with the application of the orthophosphate sources monoammonium phosphate and nitrophosphate compared with the polyphosphate source ammonium polyphosphate. The 40 kg P ha~(-1) application enhanced the uptake of N, P, calcium, sulphur and boron. No applications of P lead to increased N, magnesium, copper and zinc concentrations.