Sowing date and maize response to the splitting of nitrogen side-dressing fertilization

Abstract

The splitting of nitrogen side-dressing fertilization with the application of a nitrogen dose at maize tasseling may increase grain yield, mainly when the crop is sown at the most favorable date to achieve high productivity. This research was carried out to evaluate the effect of sowing date on the response of maize to the splitting of nitrogen side-dressing fertilization at different growth stages. Two sowing dates were tested: preferential (10/15/2015 and 09/20/2016) and late (12/5/2015 and 12/5/2016). Six nitrogen side-dressing management treatments were evaluated at each sowing date: control without N; complete nitrogen rate applied at phenological stages V5, V10 and VT; ½ N rate at V5 + ½ N rate at V10; and ⅓ N rate at V5 + ⅓ N rate at V10 + ⅓ N rate at VT. The N rate was equivalent to 300 kg ha-1. Grain yield ranged from 8.9 to 15.3 t ha-1 in Lages and from 7.4 to 16.4 t ha-1 in Atalanta. There were no significant differences in grain yield and agronomic efficiency of nitrogen use (AE) among the treatments with the entire N side-dressing fertilization at V5 and V10 and those when the nutrient was split into two or three times, regardless of sowing date. AE was higher when the crop was sown at the preferential sowing date than in the late sowing date, regardless of N side-dressing application. The splitting of nitrogen fertilization up to the crop tasseling did not increase maize grain yield or AE.