Characteristics of population development and yield formation of rice under triangle-planted system of rice intensification at different nitrogen application amounts.

Hybrid rice combination Gangyou 527 was used to investigate the characteristics of population development and yield formation under triangle-planted system of rice intensification (TSRI) and traditional cultivation at different N application amounts.Rice plants under TSRI showed increased tiller number of plant population and percentage of productive tillers,high percentage of efficient leaf area index and photosynthetic rate of flag leaves,significantly enhanced root activity,and promoted dry matter accumulation and transportation during grain filling compared with traditional cultivation.Furthermore,suitable N application amount (200 kg/hm2) under TSRI enhanced fully rational use of soil and space resources and improved population quality remarkably,and was helpful to coordinate the conflict among effective panicle number,filled grain number per panicle,seed setting rate and grain filling rate.Applying more nitrogen (240 kg/hm2) resulted in a negative effect,leading to reduced dry matter accumulation and transportation and decreased yield,which suggests yield increase under TSRI should not rely on high nitrogen rate.