Resin-Extractable Phosphorus, Vanadium, Calcium and Magnesium as Factors in Maize (Zea mays L.) Yield

Resin extraction of soil permits evaluation of ratios of readily extracted elements and correlation of concentrations obtained with crop yield. This information provides guidance on potential genotype selection and fertility management. Two hybrids of maize (Zea mays L.), designated 2292 and 3895, were grown annually in rotational succession on a 3.2-ha site with soybean (Glycine max L.) and wheat (Triticum aestivum L.). Soil samples (0–15 cm) were extracted with ion-exchange resins and extracts were analysed with inductively coupled plasma. Data were regressed against crop yield using stepwise multiple correlation methods. Each hybrid was sensitive to unique combinations of extracted chemistries. Both hybrids of maize were sensitive to the resin-extractable V : (V + P) molar ratio and potential losses of ‡ 20 % were indicated as the ratio approached 0.2. A positive response to the Mg : (Mg + Ca) resin-extractable ratio was noted for maize hybrid 2292 in each of three successive years. Changes of yield potentials associated with the Mg : (Mg + Ca) ratio for hybrid 2292 ranged from none to ‡ 20 % as the ratio ranged from 0.2 to about 0.8. The results indicate that, in the presence of large extractable concentrations of competing or inhibitory ions, different approaches to nutrient management in the form of fertilizer nutrient analysis, application, and genotype selection are needed to overcome effects of competing ions.