Platycladus Orientalis Seed-Base Seedling Of Glowth And Root Distribution In Mountain Of Henan Province, And The Period Of Seed-Based Seedling Transplanting

At present, the mainstream method of vegetation restoration is seedling transplanting. But the limit of the container space or root cutting affects root development, which makes roots roping phenomenon, together with the tensile strength of planted trees'root significantly lower than the natural wood. Therefore, our laboratory invented "seed-base seedling technique", which is in order to let the root of a tree grows deeper and wider, just like a nature tree, and its effect has already been confirmed. This study investigates the difference of growth and root distribution between seed-base seedlings methods and sowing methods in semi-arid land of Henan Province and discusses the period of seed-base seedling technic's transplanting.(1) In Henan Province semi-arid field, we arborvitae Platycladus orientalis in two ways of base seedling methods and sowing methods to investigate its growth and root distribution after 6 months and 20 months. The result shows:seed-base seedling has advantage than seed-sowing in dry weight, plant height, root depth and length of the horizontal root. There are the following two possible reasons:First, the seed-base seedling was trained by regular sprinkling water. Second, the seed-base seedling was a course of training, which growth of the taproot was limited by air root cutting, so invasion of the lateral root in seed-base seedling was promoted, and growth had increased. In addition, and planting seedlings did not have root roping phenomenon, and the seed-base seedling did not separate at the bottom of the seed base where the air is used to quit the root, which means the seed base seedling can make the root grow like the natural tree.(2) In order to clarify the film studies of vacant basement planted root seedlings' distribution at different culture time, we set three different planting seedlings and transplanting time to survey of their growth and root distribution in 10 months. The results show:the ratio in decreasing order of bigger seedlings in plant height, root depth, root weight and the weight decreasing is:June transplanting seedlings> August> seedling> October transplanting seedlings. The ratio in decreasing order of bigger shoot is:June transplanting seedlings> August transplanting seedlings> October transplanting seedlings> seed sowing seedlings. Therefore, the greatest growth is in June, the possible reason of which is:the seed-base seedling was trained by regular sprinkling water, or the air root cutting during the seed base seedlings limited the growth of main root, which promoted invasion of the lateral root in seed-base seedling and the increase in growth after transplanting. Therefore, in order to improve the seed base's growth, root depth and the ratio of root to shoot, the most appropriate time to transplant is in June. From the point of the root distribution, the transplanting process of seed-base seedling cultured within 6 months has little effect on the main root's regeneration for the transplanted seed-base seedling did not separate from the bottom of the seed base where the air is used to quit the root and did have roping phenomenon. However, the ratio of the main root length to the lateral root length was lower than the seed sowing, which may be due to the fact that the growth of main root is limited during the progress of seed-base seedlings for the air is used to quit the root, as a result, lateral root was promoted to grow and take the place of main root's function to growth deeper and deeper. Therefore, this phenomenon may affect the distribution of seedling roots in the future.