Screening method of low-nitrogen-resistant corn variety

The invention discloses a screening method of a low-nitrogen-resistant corn variety. The method comprises the following steps: designing low-nitrogen treatment and normal nitrogen fertilizer treatment, planting a large-scale corn variety, and investigating the sowing time, seedling emergence period, powder scattering period and spinning period of corn plants; after the corn is ripe, harvesting andmeasuring the grain yield and the water content; calculating an interval difference ASID between the powder scattering period and the spinning period; calculating a low-nitrogen productivity coefficient NLP and a yield potential coefficient NNP of the corn variety; calculating a nitrogen utilization index NUI, an average nitrogen utilization index NUIA and a relative nitrogen utilization index RNUI of the corn variety, and calculating a relative low nitrogen resistance index RTNI of the corn variety; and comprehensively screening out the low-nitrogen-resistant corn variety. The low-nitrogen-resistant variety screened