Effects of Nitrogen Fertilizer Management on Yield and Nitrogen Use Efficiency of Eryou 498 in Triangle-Planted System of Rice Intensification

Abstract

Hybrid rice Eryou 498 was used to investigate the effects of nitrogen (N) fertilizer management on leaf area, photosynthetic rate in productive phase, and also dry-matter accumulation and its transportation in triangle-planted system of rice intensification (TSRI) with appropriate seedling age and density. At the same time, the effects of dry-matter accumulation before anthesis and its transportation and dry-matter accumulation after anthesis on yield formation were also explored a N fertilizer management which could both increase yield and reduce the N waste. The results showed that in TSRI N fertilizer management had significant effects on leaf area index (LAI) and photosynthetic rate except the LAI in waxy ripening stage; with the increase of N rate and postponing N application, net photosynthetic rate in flag leaf in full heading stage and waxy ripe stage increased significantly; LAI in productive phase exhibited a parabola mostly with the increase of N rate and postponing N application. In TSRI, N rate and ratio of application both enlarged total glumes to increase yield. At the same time, N rate enlarged 1000-grain weight and ratio of application improved seed-setting rate to increase yield respectively. In TSRI, dry-matter accumulation before anthesis, dry-matter of transportation, and transportation rate of dry-matter had significantly positive correlation with yield respectively. The treatment which N rate was 150 kg ha–1 and panicle fertilizer was 30% of the whole N fertilizer enlarged dry-matter accumulation before anthesis and dry-matter of transportation significantly to reach maximum yield. It also improved N agronomy efficiency and N physiology efficiency significantly, so it was the best combination which could both increase yield and reduce the waste of N fertilizer to the maximum degree.