Water-retaining agents are divided into starch, cellulose, and synthetic polymer based on the source of raw materials. They all have the characteristics of being insoluble in water, insoluble in organic solvents, and capable of absorbing water from hundreds to thousands of times their own weight, but starch and cellulose The product is easily corrupted and invalid. Applying water-retaining agent when raising seedlings and planting trees and shrubs in the nursery can greatly improve the survival rate of seedlings and promote the early growth of plants. In the past ten years, hundreds of forest farms, farms, farmers, and greening companies have used water-retaining agents to plant fruit trees, transplant trees, shrubs, and vines under the guidance of experts. The survival rate has increased significantly, greatly reducing the cost of transplanting (especially high value Transplanting large trees) risk of death.
1. Nursery garden
Applying water-retaining agent in nursery fields where cutting, grafting, tissue culture seedlings, seed breeding, and irrigating seedlings are applied, seed germination and rooting of cuttings will be accelerated, and seedlings will grow faster and more robust, and in the process of transplanting The impact is also very small. According to different seedling breeding and planting methods, the water retaining agent can be mixed into the topsoil layer by spreading, hole application, or furrow application.
Experiments have shown that the growth of seedling roots will extend into the water-retaining agent crystals. If each plant root can carry 50-200 water-retaining agent crystals, the transplanting process can greatly reduce the adverse effects of drought on transplanting and growth. For some plants that are difficult to transplant, the survival rate of seedlings can also be improved.
2. Seedling dipping root
After the bare root seedlings are excavated, they are faced with the problem of root dehydration affecting survival in the process of packaging, transportation and temporary storage. Dip the seedling roots in the mud mixed with clay, water-retaining agent and water can be much better than dipping other materials (such as wood chips) as a humectant. Because the water-retaining agent has a larger water content, and even if the powdered water-retaining agent is used, it still retains the inherent diamond shape after absorbing water, which can keep the roots breathing normally while moisturizing. The preparation ratio of the moisturizing mud is fine-grained water retaining agent: slime: water=1:150:200. Calculated on the basis of 100 grams of this water-retaining agent slurry per seedling sticky tape, the cost of the water-retaining agent used per plant is only 0.02 yuan.
3. Seedling transplanting
When planting seedlings of bare-rooted trees, shrubs and vines, when backfilling the planting hole soil, apply 1-2 cups (250-500g) of water-retaining agent hydrogel to the roots of the seedlings, and then fill the soil. The cost of applying water-retaining agent per seedling is only about 0.06-0.15 yuan, and the risk of seedling death can be reduced by more than 50%.
In recent years, in order to make the application of water-retaining agent convenient, fast, and accurate, it has also developed and produced rapid seedling planting equipment suitable for planting coffin seedlings. A single person can plant 5-6 seedlings per minute. It is especially suitable for large-area artificial afforestation and afforestation in arid mountains. When transplanting large-sized bare-rooted trees, it is recommended to use gel-type water-retaining agent, but if it is convenient to irrigate when planting, dry-particle water-retaining agent can also be mixed in the backfill and landfilled around the roots of the transplanted tree. The method of transplanting tree and shrub saplings with soil balls is to mix the water-retaining agent dry particles or hydrogel with suitable filling soil, and backfill them to the root soil 10 cm below the surface of the soil ball.
Regardless of transplanting bare root seedlings or soil ball seedlings, if dry-grain water-retaining agent is applied, sufficient water must be filled twice within 24 hours after planting and backfilling to ensure that the water-retaining agent particles in the soil are fully absorbed. Play the role of water retention and water supply.
4. Tree transplantation
The use of water-retaining agent is one of the main technical guarantee measures for the "site formation" of large trees with canopy transplantation. Combining with premature root cutting (limiting the root width and stimulating the formation of new root caps), proper pruning and removing leaves (reducing water consumption by transpiration), moisturizing the trunk, applying transpiration inhibitors and rooting agents, and controlling burial depth, etc. After the tree is transplanted, the water balance is quickly restored, and the survival rate of transplanting in summer can reach 95%.
Dig a hole 80 cm wider than the root diameter of a plant, mix most of the excavated soil with the water-retaining agent, and leave a small part as the top soil. After the plants are in the pit, they are filled with soil mixed with water retaining agent. Cover the surface of the pit with the reserved topsoil and pour thoroughly. The surface of the pit is made into dimples or ridges to facilitate gathering rainwater and irrigation. The amount of water-retaining agent is that the hydrogel accounts for 30% of the backfill, or the dry particles account for 0.3% of the backfill.
5. Deal with growing trees
For fruit trees with weakened trees or reduced yields due to soil drought or other factors, in the vertical projection range of the canopy, combined with digging ring ditches (ditches), applying organic fertilizers, mixing the preservatives and applying them to the roots of the trees. Area.
Drilling and soil improvement is a better way to apply water-retaining agent to growing trees. Using mechanical earth augers with high work efficiency, simple operation, time-saving and labor-saving, drill down holes at fixed points under the canopy area, and quantitatively mix the water-retaining agent and organic fertilizer with soil backfill into the hole. Compared with the traditional ring ditch method, strip ditch method, radial ditch method or plowing man-soil method, the drilling method has more advantages.