Compositional Nutrient Diagnosis in Maize Grown in a Calcareous Soil

Preliminary compositional nutrient diagnosis (CND) norms for maize (Zea mays L.) were developed from a small database as means and standard deviations of row-centered log ratios V(X) of five nutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] and a filling value R, which comprised all nutrients not chemically analyzed and quantified in 72 leaves of hybrid 'Pioneer 3044.' Norms were derived from maize grain yields higher than 7.7 t ha-1. Principal-component analysis performed using CND nutrient indexes allowed us to identify an antagonism between N and Mg explained by the calcareous nature of the soil and the relevant N fertilization with ammonium (NH4+), and a positive interaction between P and K, and P-Ca and K-Ca antagonisms. Maize plants tended to take up lower amounts of N and K and higher amount of Mg in our calcareous soil than the concentrations of these nutrients reported to be optimum.