不同类型基质对机插水稻秧苗生理特征及产量的影响

摘要

为解析基质的类型特征、秧苗生理特性、机插质量和产量间的内在联系，评价育秧基质的适用性与应用广泛性，该研究以营养土为对照，以2种代表性的基质类型（混合基质和轻型无土基质）为研究对象，研究了不同类型育秧基质对水稻秧苗生长特征、大田机插质量、生育期和产量形成的影响。结果表明，轻型无土基质和混合基质容重均显著低于对照，分别比对照低85.19%和74.07%（P＜0.05），通气孔隙、持水孔隙和养分含量显著高于对照（P＜0.05），育秧工序简单操作。轻型无土基质和混合基质所育秧苗地上部生长特征与根系生长特征显著优于对照处理（P＜0.05），根系盘结成块，漏插率分别比对照低4.17%和4.32%，达显著差异水平（P＜0.05）。轻型无土基质的伤秧率为3.07%，和对照无显著差异，但显著低于混合基质（P＜0.05）。轻型无土基质和混合基质水稻大田机插后，分蘖发生分别比对照处理早4和2 d，全生育期缩短2 d。轻型无土基质与混合基质处理的水稻库容量分别比对照高14.01%和10.67%；产量分别比对照高5.30%和6.14%，均显著高于对照处理（P＜0.05）。轻型无土基质与混合基质理化属性优于对照处理，培育秧苗与机插技术兼容性强，利于工厂化育秧基质的开发，其中轻型无土基质是由由作物秸秆加工而成的无土基质，更适宜于基质的生产与应用。%With the expansion area of mechanized-transplanted rice, the demand to high quality of rice seedling becomes more and more important. Traditional seedling raising pattern such as use of nutrient soil is difficult to meet the growing demand of mechanized-transplanted rice seedling. It is predicted that in the future, there will be more seedling substrate to replace nutrient soil for raising rice seedling. Thus the research for physical and chemical properties of seedling substrate, seedling physiological characters from those substrates, mechanized quality, grain yield and relationship among those are very important for selecting a proper substrate for raising rice seedlings. In this study, we used three different types of rice seedling substrate treatments: nutrient soil (CK), light soilless substrate and mixed substrate to determine the relation among physical and chemical properties of seedling substrate, seedling physiological characteristics, mechanized quality and grain yield, and to evaluate their adaptability and applicability. The results showed that volume-weight of light soilless substrate and mixed substrate were 85.19% and 74.07% lower than the control treatment, while the aeration porosity, water-holding porosity and their nutrient content were significantly higher (P<0.05) than the control. Seedling age and plant height and shoot weight and shoot width showed advantage compared with that of the control treatment. Their seedling roots that can coil into a block and empty cone rate were less than 5%, and both were 4.17% and 4.32% lower than the control, respectively (P<0.05). With more dry matter accumulation in seedling stage, the seedlings from two substrate treatments regrew quickly and tillers started earlier after transplanted in field, resulting in the advancement of tillering stage and heading stage compared with the control treatment. The initial tiller stage of light soilless substrate treatment was ahead for four days than that of CK, and mixed substrate was two days. In both substrate treatments, rice was two days shorter in their total growth duration compared to that of CK. Light soilless substrate rice accumulated more root and shoot dry matter in seven days after transplanted, but after 14 days, Mixed substrate rice behaved the same in dry accumulation with soilless substrate rice. From both substrates, rice had significantly (P<0.05) more dry matter accumulation than that of the control treatment in all growing stages. More dry matter accumulation in tiller stage and strong root system in tillering stage helped the tillers to fade slowly, which led to more effective tillers per plant and more numbers of panicle than that of the control treatment. Yield and storage capacity (number of kernels and kernel size per plant) of light soilless substrate treatment and mixed substrate treatment were significant higher than the control treatment. The range of increased storage capacity were 14.01% and 10.67% (P<0.05), and yield were 5.30% and 6.14% (P<0.05), respectively. This study indicated that the physical and chemical properties of light soilless substrate and mixed substrate were superior to the control treatment, and their seedlings were suitable for mechanized transplanting technology. This was helpful to the development of industrialized seedling substrate product. Light soilless substrate is made of crops, straw, which is easy to get and can be decomposed completely in soil. Moreover, lighter in weight of light soilless substrate helped to reduce labor intensity and lower in water content helped to prolong the storage life. The yield from light soilless substrate was almost the same with the mixed substrate treatment, but was significant higher than that of control (P<0.05). With the obvious application advantage above, light soilless substrate was better for the production and application of seedling substrate.