Grafting water-retaining agent containing super-high humic acid content for agriculture and forestry and preparation method of water-retaining agent

Abstract

The invention provides a grafting water-retaining agent containing the super-high humic acid content for agriculture and forestry. The water-retaining agent is prepared from, by weight, 30%-70% of humate, 5%-30% of starch, 5%-35% of main cross-linking agent, 0.01%-0.5% of auxiliary cross-linking agent and 0.05%-0.5% of initiator, and the raw materials are polymerized in an aqueous solution. A surface structure of the grafting water-retaining agent containing natural polymer of humic acid and the like for the agriculture and the forestry has ionic type hydrophilic groups of -COOH and -COO<-> and various non-ionic type hydrophilic groups of -NH2, -NH-CO-, -COO- and -OH; meanwhile, structural characteristics of the humic acid are achieved, and the characteristic of an amorphous state is embodied.

Description

technical field [0001] The invention belongs to the field of preparation of agricultural and forestry production materials, and in particular relates to a graft type agricultural and forestry water-retaining agent with ultra-high humic acid content and a preparation method thereof. Background technique [0002] Water-retaining agent is a new type of functional polymer material, which can absorb water tens to thousands of times its own weight in a short period of time, and the gel formed after absorbing water and swelling is not easy to separate out water under pressure. When the relative humidity of the environment decreases, it can slowly release water, which can be called a "small reservoir" for plant growth when used in agriculture and forestry. Therefore, water-retaining agents have a wide range of uses in water retention and drought resistance, water-saving crop production increase, afforestation, desert control, crop seed coating, improvement of germination rate, preve...

AI Technical Summary

Problems solved by technology

[0003] However, from the perspective of practical application, the current agricultural water-retaining agents usually have single performance and no targeted synthetic water-retaining agents

Although this type of water-retaining agent has a high ability to absorb deionized water, it still has the following problems: (1) Poor salt-alkali resistance

When applied in soil, the water absorption rate of agricultural water-retaining agents on the market will be far lower than its water absorption rate in deionized water, so it is very unsuitable for some areas with high groundwater hardness in central and western my country

(2) Repeated water absorption capacity is poor

Due to being easily affected by water hardness, the repeated water absorption capacity of agricultural water-retaining agents on the market is very low. After repeated water absorption and release once or twice, its water absorption rate will be less than 50% of the initial water absorption rate.

(3) Low mechanical strength, easy to break in soil

Due to poor salt and alkali resistance and poor repeated water absorption, if you want to increase the repeated water absorption times of the water retaining agent, you can only increase its initial water absorption rate as much as possible

As a result, its mechanical strength is much lower than the practical use level in agriculture and forestry

In addition, if the initial water absorption rate is too high, it will cause water-retaining agent and crop roots to grab water, which is very unfavorable for crop growth and development.

(4) If the agricultural water-retaining agent on the market is used in the soil for a long time, it will easily cause soil compaction and acidification, which is not conducive to crop root respiration

(5) The production cost of agricultural water-retaining agents on the market is high and expensive. Usually, the market price of such water-retaining agents is more than 25,000 yuan / ton, which cannot be used as basic agricultural production materials

(6) Some varieties of agricultural water-retaining agents are difficult to degrade naturally in the soil, and the water-retaining agents that can be naturally degraded have very low salt and alkali resistance and mechanical strength

(7) Single performance

[0009] (3) The reaction temperature of the patented preparation method is too high, which will cause humic acid to lose its activity

[0010] (4) It is a mistake to directly mix nitrogen, phosphorus and potassium fertilizers in the water-retaining agent in the preparation method of the patent

There is a consensus in the industry that water-retaining agents and NPK fertilizers are applied to soil separately, and the description method is not scientific

[0011] (5) As described in the patent, after forming a viscous gel-like product, the practice of mixing nitrogen, phosphorus and potassium fertilizers into it is suspicious

Because the material is highly viscous at this time, even the stirring paddle in the reactor cannot be stirred normally, and it must be shut down

If it is forced to stir, it will cause engine damage

Therefore, in actual production, the method of mixing NPK fertilizers cannot be mixed by stirring

If nitrogen, phosphorus, and potassium fertilizers are forcibly added without stirring, the product will be extremely uneven and the product quality will not be satisfactory.

Therefore, the patent described here does not have practical operability

[0012] (6) The color of the product described in the patent is "yellow-black", which is not in line with the actual situation according to the experience of industry insiders

Since the basic performance parameters it claims as a "water retaining agent" are not provided, readers cannot understand whether the product it describes really has the basic water absorption capacity

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