Soil water retention agent is a high molecular polymer with high water absorption and water retention capacity. It can quickly absorb pure water hundreds or even thousands of times heavier than itself, and has the function of repeatedly absorbing water. The water it absorbs can slowly supply Plant absorption. At the same time, it can reduce surface runoff, reduce soil moisture and nutrient loss, and improve water and fertilizer utilization. The application of water retaining agent in the field of landscaping has good effect and great potential, which can greatly improve the quality of the project and reduce the cost of the project and management.
1 Soil application method of water retaining agent
There are two methods for applying water-retaining agent. The details are as follows: One is to make the water-retaining agent absorb water and form a gel before mixing with soil; this method is the best, suitable for arid areas and areas with poor water and fertilizer retention. Second, do not absorb water and mix with 300 to 1,000 times the soil before applying, and water after application; it is suitable for areas with a lot of natural rainfall, and this method is used for soil with good irrigation conditions and good water retention and fertility; dry application, do not apply Step on the soil to keep the soil loose. After watering, the water-retaining agent has room for swelling by absorbing water, avoiding the expansion of the water-retaining agent and being squeezed, reducing the water absorption rate, reducing the soil air, and affecting the absorption and growth of roots.
2 Application of water retaining agent in landscaping
2.1 Application of water retaining agent in nursery
2.1.1 Ground casting method. When spreading and raising seedlings, after leveling the border surface, mix appropriate amount of fine soil with the water-retaining agent (facilitates evenly spreading), and evenly spread it in the border. Use the head to turn and plan the soil to make the water-retaining agent evenly distributed in the soil layer of about 10 cm. , Ping flat border noodles, pour water twice to make the water retaining agent absorb enough water, sow seeds and cover soil.
2.1.2 Sowing (cutting) channel casting. When drilling seedlings or cuttings, after the sowing (cutting) ditch is opened, the water-retaining agent is mixed into the fine soil and sprinkled in the ditch, and the soil at the bottom of the ditch is mixed with a tool such as a narrow head to make the water-retaining agent evenly distributed in about 10 cm of the bottom of the ditch In the soil layer; sowing and raising seedlings, watering in the ditch, and after the water seeps down, water it again to make the water retaining agent fully absorb the water, and finally plant and cover the soil. Cuttings are used to raise seedlings. After applying water-retaining agent in the furrow, insert cuttings along the furrow, cover the soil to level the border, and irrigate.
2.2 Application of water retaining agent in tree (sapling) planting
2.2.1 Root mud method. Water retaining agent and soil are mixed in a ratio of 1:200-300, and water is added to form a slurry. When the tree (sapling) is planted with bare roots, the root system is dipped in mud and planted. For the exported trees (saplings), the root system is dipped in mud and covered with agricultural film. The root system can not lose water for a long time (5-10 days), which improves the survival rate of planting.
2.2.2 The planting pit (ditch) casts a spell. Water-retaining agent and soil are mixed and mixed well at a ratio of about 1:1 000. When planting, apply the mixed soil around the roots of the tree (seedling), and then cover a layer of garden soil; the tree (seedling) planted with a soil ball For wood, the mixed soil can be applied around the soil ball, and the upper part is about 10 cm covered with a layer of soil; after planting, irrigate twice with water to make the water retaining agent fully absorb water. For planting on land where the soil is infertile, water and fertility are poor, and there is no convenient irrigation conditions, it is best to make the water-retaining agent absorb enough water, and then mix it with the soil before applying it. Water retention dosage: apply water retention agent 150～300 g/plant for large trees with a diameter of more than 10 cm, and apply water retention agent 10～100 g/plant for small trees. When planting hedges and color blocks, apply it in the planting ditch, and apply water-retaining agent 20-30 g/m2.
2.3 Application of water retaining agent in lawn planting
Sowing grass seeds: After leveling the ground, mix part of the fine soil or sand with the water retaining agent (easy to spread evenly), and sprinkle it on the whole ground, mix well with a hook or shackle, so that the water retaining agent is evenly distributed in 6-10 In cm soil layer, level the ground, sow grass seeds and cover soil after irrigating twice. Spread the turf: first sprinkle in the water-retaining agent, mix well, level the ground, spread the turf, water 2-3 times, and apply the water-retaining agent 15-30 g/m2. When planting lawns on slopes, you can fully absorb the water retention agent, mix it with part of the dry soil, make it loose, and sprinkle it on the well-maintained ground, mix it with a hook or sprocket, and spray water after leveling to make the soil soak Seed and cover soil after layer 10-15 cm. Pay attention when laying turf. Sprinkle water-retaining agent first, mix well and level, and spray water after laying turf.
2.4 Application of water retaining agent in garden flower management
In garden management, the methods of applying water-retaining agent to trees include radial furrow method, ring furrow method, strip furrow method, and hole method, which are the same as fertilizer method. When applying, usually ditch or hole within the outer edge (drip line) of the projection of the tree crown. The size of the ditch (hole) and the amount of application depend on the size of the tree. Generally, the depth of the groove (hole) is 30-40 cm; It can be applied dry or after absorbing water, and applied to the soil layer of 10-40 cm in the ditch (hole). When fertilization is needed, apply fertilizer and water-retaining agent into the ditch (hole) and mix well with the soil, and water after application . The amount of water-retaining agent applied depends on the size of the tree, site conditions, etc. Generally, 15-20 g/m2 of water-retaining agent is applied according to the projected area of the canopy.
2.5 Application of water retaining agent in lawn management
Apply water-retaining agent to the lawn. After mowing the lawn, mix the water-retaining agent with fine soil (sand) and spread it evenly on the lawn. Use a narrow hook to loosen the soil and mix well. Apply to a depth of 6-7 cm, and pour 2 to 3 after application. Times water.
3 Precautions for garden application of water retaining agent
3.1 Types of water retaining agent used
Seedling raising generally uses starch grafted acrylate water-retaining agent. The service life of this kind of water-retaining agent is 1 to 2 years, and the tree seedling cycle is also 1 to 2 years, which coincides with the seedling cycle. Ammonium acrylate water-retaining agents are often used in management. This type of water-retaining agent has a service life of 3 to 4 years. It is effective for many years after one application, which can reduce garden management labor. In arid areas, land and slope land with poor water retention capacity, starch grafted acrylate water retention agent should be selected because of its fast water absorption rate and high water absorption rate. After watering or rainfall, water absorption is fast and more water, which is beneficial to drought resistance.
3.2 Water retaining agent should be applied deeply and mixed well
Water retaining agent should be applied deeply, generally applied in the soil layer below 10 cm, it is less affected by light, heat and drought, and has a long service life. Water-retaining agent and soil are generally mixed at a ratio of 1:300 to 1,000. If it cannot be mixed well, the concentrated area of the water retaining agent will absorb a lot of water, which will affect the air and heat of the local soil layer, and affect the growth of the local root system, and even rot the roots.
3.3 It is necessary to replenish water in time when the weather is dry
The water retaining agent absorbs and stores irrigation water or natural precipitation before it can supply water to the trees. The weather is dry and there is no rain. Generally, it is necessary to irrigate and replenish water for about 20 days; otherwise, the tree (sapling) will be affected by drought, which will affect the growth and accelerate the water retaining agent’s absorption and storage. The exhaustion of water capacity shortens the service life. Pay more attention to irrigation on plots with less water retaining agent.
3.4 Water-retaining agent, fertilizer, pesticide, mixed use
Most chemical fertilizers can be mixed with water-retaining agents. When applying chemical fertilizers, apply water-retaining agents first, mix well with soil, and mix well with chemical fertilizers. They cannot be mixed with fertilizers containing bivalent metal elements such as zinc, manganese, and magnesium. The water-retaining agent is mixed with pesticides. The water-retaining agent is first mixed with an appropriate amount of soil, and then the pesticide is added and then applied. Granules and powders can be added directly and mixed well and applied. Liquid pesticides should be mixed with water to make a liquid and sprayed on the soil and mixed well.
3.5 Comprehensive application of water retaining agent and other water saving measures
Water retaining agent can be applied in conjunction with other water saving and water retention measures. After the water retaining agent is applied, the ground shall be covered with plastic film and grass to reduce water evaporation and runoff.