Preliminary studies of the fertilizer capability of some novel high analysis multinutrient compounds

In a preliminary assessment of the fertilizer capability of three high analysis NP(S) compounds, their possible phytotoxic effects were investigated in solution culture tubes. One of the compounds was studied in more detail in pot experiments with sand and a red-brown earth soil. Two adamantane-type compounds (APA and APAS) were capable of supplying N and P to plants, but also showed toxicity effects. With APA, this effect appeared to be dissipated in soil but not in sand. The toxic effect was alleviated by addition of soluble P or soluble P + N. Some plants absorbed excessive amounts of P, probably not all in the form of orthophosphate.     

Response of two okra (Abelmoschus esculentus L. Moench) varieties to fertilizers: Growth and nutrient concentration as influenced by nitrogen and phosphorus application

The growth response and nutrient concentration in okra (Abelmoschus esculentus L. Moench) as influenced by four nitrogen rates (0, 25, 50 and 100 kg ha^–1) and three phosphorus rates (0, 13 and 26 kg ha^–1) were examined using two varieties (White velvet and NHAE 47-4). Nitrogen application generally increased fruit and shoot dry weights markedly whereas phosphorus increased them only moderately. Leaf and primary branch production and plant height were also enhanced by nitrogen fertilization up to 100 kg N ha^–1 but were not influenced by phosphorus application. The application of nitrogen enhanced the concentration of N, P and K in fruits and N and Mg in leaves while P and K concentrations in leaves were depressed. Nutrient concentrations in plant tissues were also partly a function of plant age and variety.