Study on the Interaction Mechanism of SAP and Fertilizer an Soil

In the actual production at home and abroad, the specific application technology of water retention agents can be summarized as follows.

The name Superabsorbent Polymer was first translated from the Japanese, and the common international name is Super absorbent polymer (SAPs). Water retention agent was first developed in the 1960s by the U.S. Department of Agriculture Northern Research Institute using corn

Water retention agent is also known as soil water retention solution, high water absorption value, high water absorption agent, polymer water absorption agent, is a kind of polymer with super high water absorption and water retention ability made by using strong water absorption resin. This polymer can quickly absorb hundreds or even thousands of times more water than its own species. It absorbs water and swells to produce a gel, and can retain water for a long time, unlike paper and cotton as easy to lose water, even if the pressure is added, the water absorbed is not easy to separate out. Water retention agent has a strong hydrophilic, but it does not dissolve in water itself, and can repeatedly absorb water, water release, enhance the water retention capacity of the soil for plant absorption and use.

In the process of agricultural production, water retention agents can be used for seeding, seedling and transplanting, as well as for ground cover, soil improvement and long-distance transportation of seedlings. In the actual production at home and abroad, the specific application technology of water retention agents can be summarized as follows.

1. Seed coating

This method is actually the same as the seeds to wear a special function of the "coat". This "coat" can supply the water needed for seedling growth, moderate the intense changes in low temperature day and night, reduce the risk of soil diseases, and play a role in protecting the seeds and seedlings.

2. Seed dressing

In recent years, for grain crops in corn, wheat seed dressing application of more reports. The general method of application is to first use the water retention agent to absorb water to saturation. Then dilute the saturated gel solution 20 times with water, and then pour the crop seed into the diluted solution, while stirring until uniform. The crop seeds are then poured into the diluted solution and stirred until uniform. The seeds are left to stand for 4-5 hours until there is no adhesion on the seeds and are watered until the soil is saturated. Generally speaking, the amount of 1kg of gel solution for wheat is 30-40kg, for peanut, corn, soybean, sorghum, etc. is 40kg, and for cereal, cotton bell (unthinned) is 30kg.

3. Mixing water retention agent and soil

Soil mixing refers to a method in which water retention agent is mixed directly with soil in a certain ratio for crop use. According to the different application methods can be subdivided into dry application method, wet application method and stick application method.

The basic use of the dry application method is for rainforestation, especially for large seedlings in the rainy season.

The wet application method refers to the method of applying water retention agent in gel form directly into the silviculture pit, which is more widely used and suitable for silviculture and seedling transplanting in various seasons. Before use, the dry water retention agent is poured into a fixed container and stirred while adding water until it is saturated with water, and then the gel water retention agent is mixed with the soil.

Stick application method, also known as gel net bag method. The water retention agent gel solution is fully absorbed and saturated into a cylindrical net bag made of webbing or non-woven fabric, and then the net bag is bought into the root system of the planted seedlings.

4. Seedling dipping

Seedling dipping is one of the most common methods in forestry to improve the survival rate and preservation rate of forestation seedlings. The general method is to make a hydrogel solution of water retention agent in accordance with the mass ratio of 0.5%-1%, soak the root system of seedlings in it for 8-10h and then remove it, and use plastic film or straw mat to wrap the root system of seedlings for transportation. Seedlings dipped in the root treatment itself after the formation of a protective film on the roots, coupled with plastic film and other water retention measures, not only to prevent the evaporation of water to extend the drought tolerance of plants, but also to prevent mechanical damage to the root system to protect seedlings.

5. Field crop application

Agricultural field crop application methods mainly include surface spraying, furrow application and hole application. Surface spraying is to sprinkle water retention agent directly on the surface before planting crops, forming a layer of water retention film on the surface of the soil, which can inhibit the evaporation of soil water and prolong the effective water content of the soil.

6. Cultivation substrate without figure

Mix the water retention agent with the nutrient solution in a certain proportion, and then mix it with other soilless substrates in a certain proportion, that is, soilless cultivation substrate. It can be used for potted plants, greenhouse nursery, vegetables, seedlings, flowers and other factory flowers without figure nursery. Water retention agent can also be mixed with nutrient solution alone in a certain proportion to form a gelatinous water dispersion for rice factory soilless seedlings.

7. Fluid seeding

Germinated seeds and water retention agent plantain leaves are mixed in appropriate proportions and then sown in the ground with a fluid seeder. This release does not harm the already germinated seeds when sowing because of the use of flexible water retainer gum fluid. Studies have shown that spinach taking the fluid weight retention method not only emerges 7-8 days earlier than the conventional hand sowing method. And the seedling emergence rate is also high. Fluid sowing of seeds germination should not be too long, to bud no more than 2mm is appropriate.