Effects of different seedling nursery substrates and water management modes on seedling quality and yield of mechanically transplanted rice

In order to develop a suitable technology for mechanical transplanted rice, a middle-season hybrid rice 'Huiliangyou6' was used to study the effects of nutrient soil dry bed nursery (ND), nutrient soil wet bed nursery (NW) and silt-water nursery (SW) on seedling quality and grain yield. The study also analyzed the effects of different seedling nursery methods on seedling flexibility, re-greening and spike formation stages. The results showed that for three seedling nursery treatments, seedling quality in ND was the best and SW the worst on 21 days after sowing. Compared with SW, seedling in ND and NW treatments had higher root-shoot ratio, stronger root development and higher dry matter accumulation. In ND treatment, seedling age range suitable for mechanical transplanting was 18-30 days. Also among the three seedling nursery methods, seedling flexibility was highest in ND. The nutrient soil dry bed nursery not only stabilized seed setting rate and 1000-grain weight, but also significantly increased the number of effective panicles and population total spikelets; significantly increasing yield. Seedlings re-greened very fast under ND method and also exhibited early tiller development and strong root development. This seedling nursery method was better for coordinating rice growth among the different growth stages in the field. It was also beneficial for construction of excellent population and high-yield.