Source–Sink Balance Optimization Depends on Soil Nitrogen Condition So as to Increase Rice Yield and N Use Efficiency

Genetic improvement has been devoted to increasing rice yield by the spikelet number per panicle and spikelet/leaf ratio. As a result, indica-japonica hybrid “Yongyou” varieties with large panicles superhigh potential have developed. These exhibit significantly higher grain nitrogen use efficiency for (NUEg) under moderate high N supply conditions due their sink size, but performance remains obscure low input soil fertility conditions. In present study, we investigated four including Yongyou2640 (YY2640, large-panicle india-japonica variety), Yangliangyou6 (YLY6, two-line indica Quanyou6 (QY6, three-line Huanghuazhan (HHZ, inbred variety) two treatments [LF (removing half of depth) CK] fertilizer rates (0 100 kg ha−1) in Central China. The results showed that YY2640 was more responsive than other varieties, which 19.4–42.3% three CK N100 treatment, it 14.5–19.4% lower YLY6 QY6 LF N0 N100. A ratio resulted biomass partition rather leaves Slightly post-flowering dry matter obtained from leaf content crop growth rate failed compensate adverse effects reduced pre-flowering accumulation stem-to-grain translocation during filling. This led NUEg Based on these findings, study suggested source–sink relationship super should be optimized according condition.