Effect of Nitrogen and Sulfur Fertilization of Corn on Grain Nutrient Composition

Corn is the main ingredient used in poultry feeds, representing more than 60% of the diet. Through fertilization of corn crops, changes in grain nutrient composition may be expected. A trial was conducted to evaluate the effect of several fertilization strategies on the nutrient content of corn. A 2x2x2 factorial arrangement was performed considering, 2 corn genotypes (Yellow dent or Flint corns) x 2 levels of Nitrogen (N) fertilizer (0 kg/ha or 50 kg/ha at tasseling) x 2 levels of Sulfur (S) fertilizer (0 and 20 kg/ha at sowing). All treatments were fertilized at sowing with N at a rate of 100 kg/ha. The results of yield (MT/ha), Crude Protein (CP), Lipids (L), Crude Fiber (CF), Ash (A), Amino Acids and True Metabolizable Energy (TME) were evaluated along three consecutive years. Adult roosters were tube fed for TME determinations (Sibbald method). Since the results showed no interaction (p>0.05) data are presented considering main effects.

Genotype: Yield and A was lower (p=0.05) for Flint corn than for Yellow dent corn, while CP, CF, Met+Cys, Lys and TME resulted higher for Flint corn.

N fertilization: A significant (p=0.05) increment in yield, CP, CF, Met+Cys and Lys was observed.

S fertilization: The results showed that the S fertilization significantly (p=0.05) improved yield per hectare, with no impact on the other evaluated parameters.

Conclusions: a-Flint corn had lower yield and better nutritional value than Yellow dent corn; b-Fertilization with N improved corn yield, CP and AA acid content of both genotypes; c-Fertilization with S improved corn yield without affecting their nutritional value.