Analysis on forestry seedling raising technology
Forestry seedling raising is the foundation of forestry industry development. The quality of forestry seedling raising technology directly affects the survival rate of trees. Only good seedling raising technology combined with good forestry management can ensure the quality of seedling raising. With the development of economy, forestry industry has gradually become the strategic task of China's western development. To continuously strengthen the pace of construction in the central and western regions, it is necessary to have good forestry seedling raising technology as the fundamental guarantee; Next, I would like to share a model essay from the paper web forestry paper /nykxlwo/lylw/ column of the top journal.
1. Present situation of forestry seedling raising
For many years, China's forestry has mainly adopted traditional seedling raising techniques, such as plastic bags, honeycomb paper and pepper tubes. These methods generally have problems such as thin roots, curly roots, thin roots and partial roots, which are the defects in forestry seedling raising technology in China and also a major reason for the low yield of artificial raw material forests in China. Through the development of seedling container and seedling management, forestry seedlings have been developed.
2. Forestry seedling container technology
It is generally believed that container seedling afforestation should have a good afforestation effect because the container can completely protect the root system, but for a long time, the problem of inferior root system that may occur in container seedling cultivation has not been recognized. The stand built with deformed root seedlings has no future. Scientific seedling container technology has improved the traditional seedling raising technology and method, and made the survival rate of seedlings reach a new high.
2. 1 Basic principle and development trend of container seedling raising
Traditionally, in forestry seedling raising, people think that the purpose of using various containers for seedling raising is to improve the survival rate of afforestation. But the more fundamental idea of container seedling raising is to cultivate balanced roots, cut roots by gas (form root callus) and rejuvenate propagation materials. At present, most kinds of seedling containers have been eliminated, and single, easy-to-penetrate, easy-to-decompose and non-recyclable containers have become the mainstream. There are only a few kinds used on a large scale in various countries. Technically speaking, the Fertiss non-woven container in France is the most advanced. The latest round containers for compressed cakes are also becoming more and more popular. This container is made by adding slow-release total fertilizer to the substrate. It is very small after drying and compression (similar to compressed towels), so it is very convenient for long-distance transportation and sales.
2.2 container seedling technology operation technology control
(1) container seedbed, neatly discharging containers for management; (2) Ensure that the substrate is full of containers and moist, and the substrate should use fertile forest soil; (3) Ensure that the seedlings do not lose water. During the seedling irrigation process, follow the seedlings well and always keep the roots of the seedlings moist; (4) Ensure that the seedling root system is not nested and exposed, and cut off the long seedling root system; (5) Provide water in time, ensure water supply after the container is full, and water the seedlings in time to ensure that there is no shortage of water and keep them moist. By doing the above inspection well, we can manage the above seedling stage in time and correctly in practice, protect the seedling root system to the maximum extent, improve the seedling survival rate, change the disadvantages of forestry seedling raising in China, and effectively improve the forestry seedling raising technology.
2.3 scientific seedling container technology
As the most advanced production technology, non-woven seedling container is characterized by using light matrix and non-woven materials, and making a through-bottom container with a machine. The machine automatically completes sewing, filling the matrix and cutting into sections for cutting, planting or transplanting tissue culture seedlings. The container forming machine has a large hopper for supplying substrates; There is a forming cylinder with a pushing screw in it, and a layer of non-woven fabric is wrapped outside the cylinder with an electric soldering iron block on it. There is an oblique opening at the end of the forming cylinder, and the non-woven fabric is automatically folded and overlapped when being pulled by the feeding stress of the screw, and the soldering iron block is bonded at the same time. The non-woven fabric is hung on the lower part of the forming cylinder. After the filled, bonded and molded containers are pushed out of the machine, they are controlled by numerical control electronic components, cut into sections with a pneumatic toothless saw blade according to the set length, and stacked on the exit platform, and then workers can pick them up and pack them. Can be made into barrels with different calibers, so as to produce containers with different calibers for seedling raising of different plants. Different cutting lengths can be obtained by adjusting the parameters on the controller. Usually, in vitro roots are cut off (dried up) naturally by stopping water for a period of time to form callus. Similarly, if the seedlings have been bred and cannot be planted, they can be kept in a critical wilting state to prevent the seedlings from growing wildly. This kind of callus is very important in the new concept of seedling raising. When using the above machine to make non-woven container, organic matter must be used as seedling substrate, and clay cannot be added. The raw materials used to prepare this matrix can be any organic matter. If non-woven fabric is an ideal infiltration material and molding machine is an ideal production equipment, then the matrix is the most critical. The light substrate is not only light in weight, but also convenient for afforestation on the mountain, and more importantly, it is conducive to cultivating strong roots.
2.4 Scientific evaluation criteria of seedling quality
Evaluating the quality of seedlings can effectively reflect the concept of seedling raising. In the past, people only evaluated seedlings according to their size, thickness and root system. However, under the same standard, seedlings may be aging seedlings. Therefore, in order to improve the evaluation criteria of seedlings, some criteria that cannot be judged from the appearance of seedlings are strengthened according to the evaluation criteria formed by advanced countries' seedling raising concepts, such as whether the cuttings have callus formation after air root cutting, whether the root system is balanced and whether it has been fully rejuvenated. On the basis of traditional evaluation criteria, combined with these evaluation criteria, the evaluation of seedling quality will be more scientific and reasonable.
3. Implement seedling technology and do a good job in seedling management.
On the basis of determining container seedling raising technology, strengthening seedling management during seedling raising can effectively apply this technology to practice. Do a good job in seed storage, soil preparation and fertilization, bed making, soil disinfection, sowing and other pre-seedling work to ensure the basic conditions for seedling raising. Before the seedlings are unearthed, the seedbed should be kept moist. When the seedlings are unearthed to about 30%, carbendazim, carbendazim and other pesticides should be used 500 times to prevent and control seedling diseases in time. Thereafter, disinfectant was sprayed every 1 week to prevent and control seedling diseases. Weeding in intertillage should be based on soil compaction, generally starting around the time when the seedlings grow real leaves, and then loosening the soil to weed every 30 days or so 1 time. After all the seedlings come out, the seedlings are thinned around 1 month, and the seedlings with weak growth potential are thinned. Generally, 400 ~ 500 plants /m2 will be left as strong seedlings, and the amount of seedlings left is15 ~180,000 plants/666.7m2.. Top dressing for new seedlings is 3 ~ 4 times a year, the first time is about 30 days after the seedlings grow completely, mainly nitrogen and phosphorus fertilizers, urea 10 ~ 12 kg/666.7m2, and then top dressing every 10 ~ 15 days. The top dressing method is mainly furrow application. The top dressing time of seedbed should be the first topdressing in the early growth stage, and then the top dressing time should be mainly in the early growth stage and the first half of the fast growth stage. Seedlings should leave the nursery before defoliation and soil freezing, or after soil thawing and before germination in the following spring. Water should be permeable before emergence. When the seedlings emerge, ensure that the seedlings are not harmed and the taproots and lateral roots are intact. If temporary transplanting is needed, ditch should be dug in a cool and dry place, and the roots of seedlings should be buried in wet soil for transplanting; Overwintering in the heel, all seedlings should be buried in wet sand, and the temperature and humidity should be checked in time to prevent mildew. Bundle every 50 seedlings, dip the roots in mud and pack. Seedling bundles should be labeled, indicating the variety, grade and quantity. Long-distance transportation should be covered with canvas, and water should be sprinkled halfway to keep moisture.
For the prevention and control of any pests, comprehensive prevention and control methods of various measures should be adopted to achieve the best control effect. The integrated control method is not a simple patchwork of chemical control, manual control and physical control, but should be applied after comprehensive analysis and weighing advantages and disadvantages according to the degree of insect pests and local actual conditions. In terms of chemical control, grub larvae have two best control periods: one is at the end of April and the beginning of May, when the larvae hibernate for a winter, they just get up and move, so their resistance is weak and they are easy to kill; The other is at the end of July and the beginning of August, when grubs have just hatched, and the light is bright and easy to kill. 50% phoxim 200 was used for control.
Double solution or 500 ~ 800 times solution of "39 1 1" emulsifiable concentrate should be used to drill holes and irrigate roots in the seedbed. When drilling holes, 2 ~ 3 holes should be drilled in different sowing ranges to form a "needle" shape.
Cover with soil after pouring to prevent leakage of seedling roots; Manual control: after leaving the garden in late autumn, the seedlings are dug and picked manually, or the seedlings are picked manually at 6-8 am after the rain in late July and early August. At this time, grubs will automatically climb out of the ground for activities because they are not resistant to water and humidity; Physical control: At the peak of emergence, the beetle adults can be killed by trapping with black light or spraying stomach toxic pesticides around the black light to prevent the pests around the trap lamp from getting worse. Adult heyday: seedlings can be sprayed with 75% stomach toxic agents such as phoxim or parathion.
Scientific seedling raising technology improves the efficiency of forestry seedling raising, but some problems need to be paid attention to, such as putting containers on seedbeds for easy management, ensuring that seedlings are not short of water, keeping roots moist, ensuring that substrates in containers are filled and kept moist, using fertile forest soil as substrates, and so on. Choosing better seedling raising techniques should also be combined with scientific management methods, so as to ensure the root growth of seedlings to the greatest extent and improve the survival rate of seedlings.