关键词: 精确播种, 等距单粒线播, 密度效应, 产量效应, 出苗率

Abstract:

【Objective】The benefit of uniform distance single seed linear seeding method could be due to its tracing position and relative stable space assigned to each individual plant in the seeding stage. Thus, the precision seeding of wheat using an uniform distance single seed linear seeding (UDSSLS) was investigated and its density effect on wheat seedling and maturing stages were analyzed in this study. 【Method】Wheat species of Ningmai 13 was used for no-till post-paddy field experiment by using UDSSLS method in 2017 and 2018. Wheat seed was linear sowing in single seed and keeping seed-to-seed distance uniformly, in 1.5 (T1.5), 3.0 (T3) and 4.5 cm (T4.5), respectively. Row distance was 20 cm. Physiological and ecological monitoring and analyzing on the stand, individual plant and organic scales were made in both seedling and maturing stages. 【Result】 The stable density effect was created with the UDSSLS seeding method. And the density effect could be expressed in both the stand, the individual plant, and the organ level. A small seed distance significantly increased the 50% emergence days. Seed grain yield of the stand increased with reduced seed distance, while no significance was observed between T1.5 and T3, while which under T4.5 was significantly lower than that under other treatments. In the stand level, stem weight and ear weight under T1.5 and T3 were significantly lower than that under T4.5. In the individual plant level, however, plant ear number, ear-bearing grain number and grain yield increased significantly with increased seed distance. No difference was observed for 1000-grain weight. Above-ground biomass yield, ear biomass and stem weight were also increased with enlarged seed distance, which clearly explained a density compensation effect. In the individual level, the distribution of each indices were observed to shift from normal distribution to L shaped distribution. In the organic level, no significant difference was observed on ear grain yield and 1000-grain weight. Only ear grain number varied amid the 2 years. No significant difference was observed for above-ground biomass, leaf weight, stem weight and ear weight under different treatments. 【Conclusion】 The UDSSLS method created stable density effect on wheat, which could be observed in both seedling and maturing staged and quantified on the stand, individual plant and organic level. Complicated interactions existed among different phenomics and scales of observation. It thus might be concluded that UDSSLS could be potentially used for wheat physiology and ecology studies.

Key words: precision seeding, uniform distance single seed linear seeding, density effect, yield effect, emergence rate