Abstract: Two maize cultivars, nitrogen (N) efficient cultivar Zhenghong 311 (ZH311) and nitrogen inefficient cultivar Xianyu 508 (XY508) were used in a two years field experiments in 2015 to 2016. One N-free treatment and four N fertilizer operations were set up under the N application rate of 225 kg/ha (100% basal fertilizer, 75% basal fertilizer+25% topdressing, 50% basal fertilizer+50% topdressing, and 25% basal fertilizer+75% topdressing) to investigate the effects of N fertilizer operation on dry matter accumulation characteristics and yield, and the differences in response to N fertilizer operation on dry matter accumulation, distribution, translocation, and yield of maize cultivars with contrasting nitrogen efficiency. There were important effects of cultivars and N fertilizer operations on dry matter accumulation, distribution, translocation, and yield and its component. The stronger root uptake ability and higher proportion of photosynthetic organs in N-efficient cultivar ZH311 significantly increased its dry matter production ability, meanwhile the lower pre-silking dry matter translocation and translocation efficiency effectively delayed the senescence of photosynthetic organs and kept higher post-silking dry matter productivity resulted in a significantly higher yield than N-inefficient cultivar XY508. Increasing topdressing ratio significantly improved post-silking dry matter productivity and yield, while the promotion for N-inefficient cultivar XY508 was obviously higher than N-efficient cultivar ZH311. The yield advantage of ZH311 over XY508 increased first and then decreased with the increasing of topdressing ratio, reaching the maximum of 1.48 t/ha at 61.35% basal fertilizer+38.65% topdressing. In summary, a balanced basal-to-topdressing N operation is conductive to N-efficient cultivar ZH311 to maintain higher pre-silking dry matter translocation and post-silking dry matter productivity to full play yield advantages, whereas higher topdressing ratio can significantly improve post-silking dry matter productivity of N-inefficient cultivar XY508 to make up for the lack of yield.

Key words: Nitrogen fertilizer operation, Maize, Nitrogen efficiency, Dry matter, Yield

CLC Number: 

• S143.1