水稻根长动态模拟和生长特性研究

Dynamic models simulating root length and growth characteristics of rice

利用水培和土培试验,并基于空心菜和莴苣的根长增长模型,对整个生长周期的水稻根系生长特性进行动态模拟,结果表明:7个供试水稻品种的根长增长模型拟合精度均达到统计显著水平,由根长增长模型可得到根长增长常数、根系最大增长速率和最大根长及其出现的时间等根系生长特性的量化指标。不同晚稻品种间平均的根系生长特性差异不大,但特优3101品种与其他品种相比有较大的差异。最大根系增长速率在不同品种间的变异系数为7.6%,时间在播种后2个月左右。土培试验表明,与不施肥相比,氮磷钾平衡施肥使根系增长常数提高57.2%,最大根系增长速率和最大根长则分别提高61.0%和65.4%,明显促进根系生长和增加根长。

Based on the water and soil cultivation experiments on rice and the root growth model of water spinach and lettuce, a model to describe the cycle and characteristics of the root growth of rice was established. Statistical significance of the model for 7 rice varieties was obtained. For instance, the model could predict the root length growth constant, the maximum root growth rate and length, as well as the time for their appearances. The water and soil cultivation experiments showed that all varieties retained a large root system at later stage of growth l no significant difference on root growth characteristics among the late rice varieties, except Teyou 31013 the variation coefficient of the maximum root growth rate among different species was 7. 6% and the time for the maximum root growth was about two months after sowing, suggesting an advantage of topdressing at this time for fertilization efficiency. The soil cultivation experiment showed that the root growth constant could be increased 57.2% by applica- tion of a balanced fertilization of nitrogen, phosphorus and potassium, as compared with no fertilization. The maximum root growth rate and root length were increased 61.0% and 65.4%, respectively, showing the apparent effect of the timed fertilization in promoting growth and increasing length of the roots for rice.