Abstract

ZAMUDIO-GONZALEZ, Benjamín et al. Physiological efficiency of N, P, K and Mg in maize H-47 and H-59. Rev. Mex. Cienc. Agríc [online]. 2015, vol.6, n.8, pp.1807-1818. ISSN 2007-0934.

The low efficiency of fertilizer use in agricultural soils negatively impacts productivity and sustainability of production systems. Rates of apparent physiological efficiency (EFA) were calculated regarding different fertilization treatments on the soil for hybrid H-47 and H-59. The EFA of a nutrient is the ratio of grain harvested in kg per kg of N, P, K or Mg in the crop's biomass for one hectare. We used a full factorial of five hybrid for eight fertilization treatments under the concept of "omission plot", a mode of minimum act by Leibniz. The "complete and sufficient" formula in kg ha-1 to harvest at least 10 t ha-1 of maize grain was: 240N-90P2O5-80K2O-60S-50MgO-380CaO (T8 ). With the successive omission of a macro nutrient we obtained: T1 (-N), T2 (-P), T3 (-K), T4 (-S), T5 (-Mg), T6 (-Ca) and T7 ("farmer" with 70% NPK dose of "full dose", but without S, Mg and Ca). Sowing with 90 thousand seeds per hectare in soil with "irrigation tip" on May 13th. Cobs and crop characteristics were measured in quadruplicate. With the contents of macro nutrient and biomass production of grain H-47 and H-59, calculating EFA, of treatments omission of N, P, K and Mg. The variables were analysed with SAS, separating the means by Tukey 5% test. The EFA, of all the fertility treatments were: for H-47 de 33.6/N, 232.4/P, 51.7/K and 553.4/Mg and for H-59 de 39.0/N, 181.1/P, 67.1/K and 421.8/Mg. EFA values change more associated with the genotype compared to omission of some macro nutrients.

Keywords : maize (Zea mays L.); fertilization efficiency; plant nutrition.