Carrier type slow-release fertilizer and preparation method thereof
Technical field
The invention belongs to the fertilizer science technical field relevant, relate to a kind of slow release fertilizer and preparation method thereof, particularly a kind of carrier type slow-release fertilizer and preparation method thereof with plant nutrition.
Background technology
Over nearly 40 years, the world Fertilizer amount of application has increased by 15 times, and grain yield has only increased by 3~4 times.From the eighties nearly 20 years till now, be the fastest period of China's applying quantity of chemical fertilizer increase, do not increase but grain yield is corresponding, this utilization ratio that just means applying fertilizer is more and more lower.In this season utilization ratio of China's chemical fertilizer, nitrogen is about 30~35% at present, and phosphorus is about 10~25%, and potassium is 35~50%, far below world developed country level.
Cause utilization rate of fertilizer low very major reason be the leaching loss of fertilizer, especially nitrogenous fertilizer and potash fertilizer.A large amount of leaching losses of fertilizer have not only caused direct tremendous economic loss, and environment and Sustainable development have been brought increasing influence, and thus human beings'health have been constituted serious threat.Thereby caused the great attention of countries in the world.
Utilizing different technological methods to improve utilization rate of fertilizer is to study how to stop or reduce core in the leaching loss of nutrient problem, and sustained-controll-release fertiliser is exactly the important means that solves this key problem.Sustained-controll-release fertiliser in the ideal is meant the new-type fertilizer of can be according to the needs of plant growth and nutrient being discharged gradually.
In general, the controlled release of nutrient has 3 kinds of methods: the one, use organic nitrogen compound, and the 2nd, packing method, the 3rd, support methods.A variety of realization mechanisms are all arranged in each method.
Carry out at present with the inorganics zeolite is the release and release control fertilizer of carrier, particularly the fertile many people of zeolite-urea controlled release are in development, appear to bigger application prospect, in fact, the influences that the soil texture is caused of using little and that zeolite is a large amount of of the absolute fertilizer charge capacity of zeolite make this fertilizer application prospect also pessimistic.In the last few years, utilize the macromolecule organic carrier to carry out the research of corresponding release and release control fertilizer, and obtained preferably and made progress, gluing fertilizer (Gel Fertilizer) is exactly wherein a kind of, concrete grammar is as follows: (1) prepared polymer system, and this polymer system should be compatible with fertilizer formula, and polymkeric substance must be soluble and can produce viscosity, be generally compound of polysaccharide, make powder.(2) preparation nitrogen phosphorus kalium liquid fertilizer material, the concentration of liquid fertilizer and character are decided because of ground.(3) polymer powder is poured in the vat that fills liquid fertilizer, stirred 5~10min, cellular until reaching viscosity, the polymer powder consumption accounts for 1% of mixture cumulative volume.More than be a very coarse making step, complicated in fact possibly, but the problem of most critical is how to select or synthetic this polymer system.At first secondly the necessary toughness of these polymkeric substance is that suitable reticulated structure must be arranged, and can be by the release of mechanism control nutrient certain physical or chemistry.Polymkeric substance in the ideal should have water absorbability preferably, wetting ability and the ability of being detained nutrient.Consider the suitability of this fertilizer, this material also must be cheap and easy to get.Except that gluing fertilizer, also can imagine and rest fractionated molecule and put into some and be insoluble in water and have very macromole spatial network-type macromolecular compound (as the rubber of some blending and modifying or chemical modification), utilize the carrier hydrophobicity, speed sterically hindered or chemical degradation is controlled the release of nutrient, and this also is a direction of carrier fertilizer development.Its key issue is how to allow the nutrient molecule enter into these high molecular cyberspaces.Certain this high molecular polymer must be to degrade, and that is to say it must is environment amenable.
Summary of the invention
Main purpose of the present invention is to provide a kind of carrier type slow-release fertilizer, this fertilizer can be according to the needs of plant growth and nutrient is discharged gradually, wherein the carrier that is adopted has the ability of water absorbability, wetting ability and delay nutrient preferably, and this carrier is cheap and easy to get, to overcome the above-mentioned defective of existing in prior technology.
Another object of the present invention is to provide a kind of preparation method of carrier type slow-release fertilizer, try hard to utilize support methods to reach the slowly-releasing purpose.Support methods is meant utilizes the fertile system of confession that suitable macromolecular material wraps up for carrier or the absorption fertilizer nutrient forms, and this is actually the release and release control fertilizer that utilizes the molecular skeleton coating.
First purpose of the present invention realizes in the following manner: a kind of carrier type slow-release fertilizer, have the essentially consist of general chemistry fertilizer, and its key is that it also includes carrier substance.
Described carrier substance can comprise: synthetic carrier substance or natural carrier material, when described carrier substance is artificial synthetic vectors material, can select for use: methacrylic acid, polyacrylamide, polyvinyl alcohol, polyoxyethylene glycol etc.; And when described carrier substance is the natural carrier material, can select for use: tegument glycan and derivative thereof, pectin, starch and derivative thereof, Mierocrystalline cellulose and derivative thereof etc.According to the needs of practical application, above-mentioned carrier substance both can only have been selected for use a kind of, also more than one solid support material can be used after suitably mixing, even synthetic carrier substance or natural carrier material mixing back can also be used.
Understand corresponding carrier substance more intuitively for the ease of people, in this manual it is arranged among the table 1 according to certain classification.
Table 1, various carrier substance
In order to reach better slow release effect, after carrier substance and fertilizer fully react, preferably add linking agent again, described linking agent can be selected for use: formaldehyde, quadrol, glutaraldehyde, borax or zinc oxide etc.According to the needs of practical application, above-mentioned linking agent both can only have been selected for use a kind of, also more than one linking agent can be used after suitably mixing.
The consumption of carrier substance can not be very little, otherwise can influence its fertilizer efficiency, but the consumption of carrier substance can not be too many, otherwise can increase cost, generally speaking, the ratio of its carrier substance and general chemistry fertilizer (weight ratio) can be controlled at 0.5%-20% scope, and preferable range is 2%-15%, and preferred range is 3%-10%.
The ratio of linking agent and carrier substance (weight ratio) can be controlled at the scope of 0.05-0.5%.
Above-mentioned general chemistry fertilizer can select for use present most widely used nitrogenous fertilizer (to comprise bicarbonate of ammonia, ammonium sulfate, ammonium chloride, ammonium nitrate, ammonium sulfate nitrate, SODIUMNITRATE, nitrocalcite, calcium ammonium nitrate, urea, urea formaldehyde, isobutyl fork diurea), phosphate fertilizer (comprises calcium superphosphate, double superhosphate, fused(calcium magnesium)phosphate), potash fertilizer (comprises vitriolate of tartar, Repone K,), polynary fertilizer (comprises ammoniated superphosphate, nitrophosphate fertilizer, ammonium phosphate sulfate, ammonium phosphate, ammonium metaphosphate, potassium primary phosphate, phosphorus potassium complex fertilizer, saltpetre, nitrogen-potassium compound fertilizer and nitrogen-phosphorus-potassium compound fertilizer), little fertilizer etc.
Another object of the present invention realizes in the following manner: a kind of preparation method of carrier type slow-release fertilizer, it is soluble in water with it at first to take by weighing a certain amount of carrier substance, by institute's certainty ratio general chemistry fertilizer is mixed with it then and it is stirred, fully the reaction back adds linking agent, fully reaction again, then remove moisture wherein, make granular after at last dry-matter being pulverized.
Soluble in water in order to help carrier substance, can be in advance that water is boiled, make it become boiling water, and then carrier substance is dissolved in this boiling water.
Described mixing process can adopt the electronic device that stirs to stir usually, and the technological process of removing moisture wherein preferably adopts the mode of vacuum drying to carry out.
Description of drawings
Fig. 1 is the elution curve that the nutrient of common urea and slow release fertilizer sample of the present invention discharges;
Fig. 2 is the cumulative leaching rate curve of common urea and slow release fertilizer sample of the present invention;
Fig. 3 is the linear analogue of slow release fertilizer sample stripping curve.
Specific embodiments
Below in conjunction with embodiment the present invention is described in further detail.
[embodiment one] takes by weighing the natural pectin of 0.2g in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ of reaction 30min put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment two] take by weighing the natural pectin of 2.0g in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ of reaction 30min put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment three] take by weighing the natural pectin of 1.0g in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ of reaction 30min put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment four] take by weighing the 0.2g polyvinyl alcohol in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the borax soln that adds 0.1ml12.5% more fully stirs under the room temperature, puts in the baking oven 50 ℃ then and dries to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine
[embodiment five] take by weighing the 2g polyvinyl alcohol in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the borax soln that adds 0.1ml12.5% more fully stirs under the room temperature, puts in the baking oven 50 ℃ then and dries to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine
[embodiment six] take by weighing the 1g polyvinyl alcohol in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, the borax soln that adds 0.1ml12.5% more fully stirs under the room temperature, puts in the baking oven 50 ℃ then and dries to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine
[embodiment seven] take by weighing 1g chitosan and 0.2g citric acid in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, other takes by weighing 1g pectin and is dissolved in the 50ml water, fully stir, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ are stirred down fully, put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment eight] take by weighing 0.5g chitosan and 0.1g citric acid in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, other takes by weighing 0.5g pectin and is dissolved in the 50ml water, fully stir, the glutaraldehyde solution that adds 0.5ml25% again, 80 ℃ are stirred down fully, put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment nine] take by weighing 1g chitosan and 0.2g citric acid in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, other takes by weighing 0.5g pectin and is dissolved in the 50ml water, fully stir, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ are stirred down fully, put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine.
[embodiment ten] take by weighing 0.5g chitosan and 0.1g citric acid in the 250ml beaker, fully be dissolved in the 50ml boiling water, add 10g urea, stir 30min under the device in electronic stirring, other takes by weighing 1g pectin and is dissolved in the 50ml water, fully stir, the glutaraldehyde solution that adds 1ml25% again, 80 ℃ are stirred down fully, put in the baking oven 50 ℃ then and dry to constant weight, to dry sample mortar pulverize, and take by weighing 0.0560g and be pressed into cylindrical particle with stamping machine
The method of application of carrier type slow-release fertilizer provided by the invention is with identical with the method for application of its compound general chemistry fertilizer, for example to use the use-pattern with urea be the same for carrier substance and the fertilizer that urea is composited, and can be used as base manure, the use of topdressing.
Below by the leaching test-results beneficial effect of the present invention is described:
One, test method: fertilizer sample is put into the chromatography column that an internal diameter is 20mm, and with the quartz sand mixing, distilled water connects the drip washing that continues to fertilizer after by constant flow pump, leacheate is collected with automatic Fraction Collector at regular intervals, measures the release rate that the concentration of collecting the nitrogen in the liquid can be learnt urea.
Two, interpretation of result: plant and use above-mentioned test method, can obtain the elution curve that nutrient discharges, as shown in Figure 1.This figure shows that urea leaching soon gets off, and the nitrogen degree is up to nearly 2500mg kg in the 1st pipe leacheate
-1, reduce to 0 very soon subsequently, and the 1st pipe concentration of fertilizer sample is about 600mg kg
-1, the drip washing of urea relatively, the decline of subsequent concn is obviously much slow that experimental results show.
Fig. 2 is a cumulative leaching rate, and as seen from the figure, urea reaches 100% stripping very soon, and the slow release fertilizer sample then is slow stripping, and through just reaching 100% stripping after longer for some time, and this accumulation stripping curve is the better linearity relation.
Fig. 3 is to the linear analogue of slow release fertilizer sample stripping curve, draws R
2=0.977, shown extremely significant linear dependence, this lays a good foundation for the sustained release of urea.
The development of this fertilizer is different from traditional coated fertilizer fully on mechanism, it is to utilize molecular skeleton to do carrier.
The carrier pectin that this fertilizer utilized is a kind of natural polysaccharide, extracts from the tankage of fruit, and it is the long-chain polymer, and electronegative, be suitable for doing carrier, effect is better, and cost can reduce to below 3 times of conventional fertilizers price, and utilization rate of fertilizer is expected to improve more than 10 percentage points.
This shows, utilize carrier type slow-release fertilizer, it can discharge nutrient gradually according to the needs of plant growth, simultaneously owing to obtain under the prerequisite of identical output guaranteeing, can reduce the amount of application of nitrogen, thereby reduce the contamination of agriculture production environment.Therefore the Application and Development of this kind fertilizer will produce the economic benefit and the social benefit of highly significant undoubtedly.