JPH08193192A - Soil conditioning composition - Google Patents

Abstract

PURPOSE: To obtain a compound fertilizer which causes little soil infertility. CONSTITUTION: This composition is prepared by coating urea or a compound fertilizer containing urea with an aqueous citrates solution of chitosan.

Description

TECHNICAL FIELD The present invention relates to a soil conditioner by combining a citrate salt of chitosan and urea.

[Prior Art and Its Problems] In recent years, large-scale development of golf courses has been carried out all over the country, and environmental pollution due to the large use of pesticides has become a serious social problem. In addition, general consumers are more oriented toward agricultural products that are produced without pesticides. It is impossible to actually respond to such social demands. However, in modern agriculture aiming at high yields by using large amounts of conventional fertilizers, the more fertilizers are used, the lower the soil fertility, and as a result, the plants themselves are weak and less resistant to pests and pesticides. It repeats a vicious circle that agricultural products cannot be produced without using. The best and most effective way to recover such degraded farmland is to use natural compost, but modern agriculture has been transformed into large-scale farming using agricultural machinery, so livestock manure is It is impossible to produce a large amount of natural compost produced by using it. There is also an attempt to improve by aggregating the soil of a thin farmland using polyacrylamide gel etc., but when polyacrylamide gel itself is an artificial chemical synthetic product, it can be It is estimated that the adverse effects on the environment are naturally large.

[Means for Solving the Problems] Recently, chitin or chitosan obtained from the shells of shrimp, crab and the like has attracted attention as an alternative to natural compost. This is a large amount of food that uses shrimp and crab, and industrial waste of a fisheries company. By using this instead of natural compost on farmland and golf courses, the use of pesticides can be reduced. It is known that this can be done. However, its effect is very slow, and it is not enough and it is not aesthetically pleasing when used on a golf course. In the present invention, chitosan obtained by deacetylating chitin is dissolved in an aqueous citric acid solution to obtain an aqueous citrate solution of chitosan. Urea or a compound fertilizer containing urea is mixed with this and used as an aqueous solution, or dehydrated and dried to be applied as powder or granules to agricultural fields, golf courses and ranches. The chitosan used in the present invention has a deacetylation of chitin and a deacetylation degree of 60 to 98%. It may also be one whose molecular weight has been reduced by chemical treatment.
Highly pure crystalline citric acid may be used as citric acid, but it is particularly preferable to use the fermentation solution as it is when citric acid is produced by a fermentation method, or use the mother liquor obtained by filtering the bacterial cells. Most desirable. In addition to citric acid, these fermented liquors contain vitamins, minerals, amino acids, sugars, and proteins that have fertilizing effects, and have the action of promoting plant growth. In order to extract crystalline citric acid from the citric acid fermentation liquor, many chemical treatments, purifications and dryings are required, and the energy and waste liquid treatment costs therefor are significantly higher than the method using the fermented liquor. Become. In the practice of the present invention, citric acid and chitosan are reacted in water to form an aqueous citrate solution of chitosan, the reaction ratio is the type of chitosan, that is, the degree of deacetylation, the molecular weight, the type of raw material. And so on. However, 100 to 500 g of citric acid is preferable to 100 g of chitosan. Alternatively, after adding citric acid in an amount more than necessary for dissolving chitosan to form an aqueous solution, it may be neutralized with sodium hydroxide, potassium hydroxide or aqueous ammonia until just before the chitosan breaks out. The amount of water used as a solvent changes greatly because the viscosity changes depending on the molecular weight of chitosan, but it is 2 per 100 g of chitosan.
~ 20L is desirable. The reaction of chitosan and citric acid in water is carried out at room temperature, but may be slightly heated to accelerate the reaction time. The reaction time ends in 2 to 10 hours, but ends when it becomes transparent. Depending on the purpose of use, it may not be completely transparent and may be used even in a partially swollen state. Next, the high-viscosity citrate aqueous solution of chitosan obtained as described above is mixed with urea or a compound fertilizer containing urea to be used as an aqueous solution, or dried to be used as powder or granules. The mixing ratio of these is not constant, but 1 kg to 100 kg of compound fertilizer containing urea or urea to an aqueous solution of chitosan citrate obtained from 100 g of chitosan.
kg is preferred.

[Effects of the Invention] The composition according to the present invention is applied to agricultural fields, golf courses,
When applied to ranch, the citric acid of chitosan attached to the surface of the sediment grains by the ammonia attached to the surface of the soil grains by the moisture and rainwater in the soil, and the urea generated by the urea decomposing bacteria in the soil. The salt is neutralized and water-insoluble gel-like chitosan is released. As a result, soil particles are aggregated. As described above, when the composition according to the present invention is used, farmland, golf course and ranch are not thinned, and there is an effect of recovering thinned soil due to heavy use of chemical fertilizers for many years. As a result, the growth of agricultural products, turf, grass and the like is improved, and the resistance to pests and diseases is increased.
As a result, the amount of pesticide used can be significantly reduced. The citric acid used in the present invention is a compound having calcium, magnesium, iron, manganese, zinc, copper, silicic acid and the like as water-soluble ions and having fertilizing effect and useful for plant growth. Urea or a compound fertilizer containing urea is an essential component for plant growth. However, when it is used as the composition of the present invention, chitosan is a natural organic substance and aggregates the soil, so that it is not thinned. The composition of the present invention, which is a highly water-soluble compound contained in urea and compound fertilizer, is covered with a film of highly viscous chitosan citrate in soil, so that the water-soluble fertilizer becomes slow-acting. , It is effective for a long period of time and causes less chemical damage such as burning of fertilizer.
When the composition of the present invention is applied to a ranch or the like, chitosan and citric acid are natural non-toxic organic substances and do not cause any harm even if they are eaten by livestock. As described above, the composition according to the present invention has many excellent features.

Example 1 30 g of citric acid is dissolved in 1 L of water. To this, 20 g of chitosan (deacetylation degree of 90% or more) is added and stirred at room temperature for 3 hours. A colorless and transparent high-viscosity liquid is obtained. This is sprinkled on 2 kg of granular urea chemical fertilizer (Chisso 16, Rinsan 18, potash 16) little by little while heating and stirring 60
It is dried with warm air at ℃ to obtain 2.1 kg of the composition.

Example 2 20 g of chitosan is added to 1 L of the citric acid fermentation liquid, and the mixture is stirred at room temperature for 3 hours. It becomes a uniform viscous liquid. Sprinkle this on 2.5 kg of urea while heating and stirring, and sprinkle little by little at 50 ° C.
And dried with warm air to obtain 2.6 kg of the composition.

Example 3 The citric acid fermentation broth is filtered to remove bacterial cells. Water is added to this to make a 3% citric acid aqueous solution. To 1 L of this solution, 20 g of chitosan is added and dissolved. This is dissolved in a solution of 30 g of urea and 50 g of Hyponex fine powder (trade name of Hyponex Co.) and 50 L of water to prepare a liquid fertilizer.

Example 4 40 g of citric acid is dissolved in 1 L of water. Chitosan 2 to this
Add 0 g and stir at room temperature to dissolve. Next, 100 g of 10% potassium hydroxide is added to neutralize a part of citric acid. This solution was sprinkled little by little on 2 kg of granular chemical fertilizer (magnesium, manganese, boron, urea-containing complex nitric acid phosphorus) and dried with warm air at 60 ° C. to obtain 2.1 kg of a composition.

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Claims (1)

[Claims] Mixed composition of chitosan citrate and urea or compound fertilizer containing urea