STUDY ON THE EFFECT OF NITROGEN FERTILIZER ON YIELD AND ECONOMIC EFFICIENCY OF SOME NEW HYBRID MAIZE VARIETIES GROWN ON RIVERBANK LAND IN THIEU HOA DISTRICT, THANH HOA PROVINCE

Abstract

Maize is an important food and livestock crop. In recent years, maize production in
our country has continuously increased (yield increased from 1.55 tons/ha in 1990 to 4.78
tons/ha in 2019). The results of experiment showed that at different doses of nitrogen
fertilizer applied for different maize varieties, N3 formula applied 175 kg N/ha on the base
(10 tons of manure + 90 kg of K2O + 90 kg of P2O5) achieved the best growth and
development values. The QT55 maize variety gained the highest yield (8.52 tons/ha) at N3
formula (175 kg N/ha). With different nitrogen fertilizer doses, the degree of damage of pests
and diseases on maize varieties was also different. QT55 variety was affected with the lowest
level of pest infection (3.1% of Ostrinia nubilalis; 3.5% of Helminthosporium and 4.1%
of Rhizoctonia solani Kuhn) at the N3 formula (175kg/ha). As for other maize varieties, the
degree of damage was as follows Ostrinia nubilalis was over 4%; Helminthosporium and
Rhizoctonia solani Kuhn were over 4%). When we applied nitrogen at the dose of N3 (175
kg N/ha) to hybrid maize varieties, the QT55 maize variety got the highest yield, achieved
the net profit of 28,950,000 VND/ha and a profit margin of 2.7 times.