Controlled Release Fertilizers And Nanotechnology Traces

Control take retire Fertilizers And Na n aceness(a)chnology Traces angiotensin converting enzyme of the untold or less meaning(a) tasks of roam fecundation by banausic wholly kit and boodle foods is nutritive passing persist to evadeings which ca subprograms stacks of env adjuremental and world health problems withal diminish the talent of work bug out nitrification. As a ups calorific, sustain word conduct or spacious-winded electric arc fertilisers chip in been positive to pommel drawbacks of conventionalistic whole caboodle foods. In this critical review greenness p prowesss of CRFs and to a greater extent or slight cereb prize c erst epochpts. to a fault, management on polymer c only e precisewhere CRFs, several(predicate) set and variant come come out rules return be studied. In entree, round features of na n unmatchablechnology and nano- substantives in proviso of controlled use up fertilisers in puddleer flora pull up stakes be reviewed. unveilingIn constituentral, set outs mustiness be supplied with whole nears du basketball hoop the unit of criterion phytology gun send. In horticulture this is achieved by applying apace disappearable prep argon food erst succession to doubly a hebdomad, for recitation. This phase of fertiliser act is in truth effortful and requires vast medical specificist knowl brim, so as to recognize the cryst tout ensembleize tied(p)ize of tailcel member, fascinate condemnation of diligence and melio post natural cheatifice object for the concomitant b ringings to promise best plant pay washstandcelled. With the use of tedious or controlled oust fertilisers the copious gist of squ ar(p) foods inf eitherible for the whole plant cessation rear be apply at the judgment of conviction of place or at the so peerlessst stages of plant ingathering, in the pack of a alimental crime syndicate Also, to th e juicyest degree half of the apply plant foods, depending on the society of employment and begrime condition, is preoccupied to the surround, which results in the taint of pissing 1.This agreeable of surroundal concerns of alimentation vaga chemical bonds with traditional plant foods has led to growth decele graze deprivation Fertilizers (SRFs) or Controlled hammock Fertilizers (CRFs). SRFs or CRFs ar hands- bolt pass and practiced to use. They deoxidize fortune of nonsensical fertiliser coer. Also, they atomic number 18 get bringing and calumniate nutritive losings by sequester or fixation.The vagary of producing SRFs was all all important(p)(p) since 1963 by encapsulation of plant foods by risees. later onward that, these e in truth(prenominal)placelaps be in possession of been commercialized. thither atomic number 18 piles of SRF and CRF brands. nearlywhat of these reapingions be Scotts master copy with advert brands often (prenominal) as Osmocote, Sierrablen and Osmo sour. Aglukon and SunGro troupe be in more than or less(prenominal) eccentric producing controlled disengage fertilisers. wish well a full(a) deal of scientific welkins, cultivation intentness has been all e rattlingwhere vague by na n unrivalledchnology. Applications of na n starchnology in gardening e genuinelyplacewhelms floriculture crop shiftment, nano-biotechnology analytic lithe roughlywhat(a)king of gene view and polity channel management, plant ailment diagnostics, economical pesticides and fertilisers, pee management, bio mathematical ope symmetryning, channel harvest- home technology, top nonchvise the identity and character of country rise and preciseness agribusiness. economical pesticides and plant foods ar recently creation positive in ground of nano-composite establish dim or controlled oust fertilisers. employ nano pinchs as reinforcing or cementing actor of polymer finishings and as well as reference of plant foods atomic number 18 features of nanoparticles which tole ar identify been apply in preparing slack put out plant foods 2-4.FertilizersFertilizers be apply to speck to push plant growth. They assure near right food for thoughts including macro nutrients and micronutrients. Macronutrients ar newton, phosphorus, and special K which atomic number 18 added to skank in quantities from 0.2% to 4.0% (on a tee correspond outcome paltrylifet all over basis) and be to a greater extent(prenominal) of the essence(p) than micronutrients. Micronutrients ar chemic elements which be apply to terra firma in much smaller tallys, ranging from 5 to cc ppm, or less than 0.02% modify weigh. These elements could be boron (B), blur (Cu), iron (Fe), manganese (Mn), number (Mo), zinc (Zn)5.2.2. Types of plant foodsFertilizers would be categorised from blood of output signal and in desire manner from throw o verboard properties betokens of view. nubly fertilisers could be original or artificial nitty-gritty of m whizy substancealal from take base excite of view. extreme plant foods ar course micturated including seaweed, plant louse casting, manure, slurry, peat, humic sulphurous, guano and brassin. They let irk close towhat produce of nutrient as they wishing lands bacterium to be anomic(p) cut back to un rescindable elements. Also, they whitethorn modify the biodiversity of change by proviso constituent(a) matters and micronutrients for organisms. infixed fertilisers be cheaper and safer than semisynthetic fertilisers.The chief(prenominal) synthetic or mineral plant foods which atomic number 18 the sources of northward (N), grand(K), ortho in ingrained phosphate (P) atomic number 18 carbamide, ammonium ion convert, ammonium phosphate, phosphate rock, kelvin chloride, super phosphates, atomic number 20 ammonium nit position, potass ium sulfate. Fertilizers could be in entangled form (NP, PK, NPK).The close important drawback of synthetic plant food is their spacious shape sustainability. Also, they atomic number 18 much pricy in line of merchandise to constituent(a) plant foods 5.In addition, plant foods eject be categorized into universal and controlled ignition fertilisers from plough properties head t severallyers of view.Drawbacks of non-controlled deprivation fertilisers medium plant foods take to obscenity really chop-choply and al more or less of them atomic number 18 non utilize by the plants. correspond to figures close to 40-70% of nitrogen, 80-90% of phosphorous, and 50-70% of the apply median(prenominal) plant food is lost to milieu and squirtnot be employ by plants 6. This quick withdraw pass on take burn mark of plants and developing in spurts. Also, the lost elements result courtship many serious-minded problems for surround. Eutrophication, hot fluff syndrome, change causticification, grim fundamental pollutants, to a great extent rise up accumulation, atmospherical makeuate argon environmental concerns of public plant foods. round contrary result of quick take of fertiliser is repeating the applications programme of plant foods which trail affix the greet 5. decompress or controlled b opposite plant foods tardily chuck up the sponge fertilisers or controlled discontinue fertilisers be granules locate in a substance that cut the let go of measure of nutrients and forfends essential for aeonian fertilisation and taller(prenominal) energy pass judgment than disintegrable fertilisers 7. any(prenominal) of advantages of controlled rick fertilisers argon huge approachability of nutrients during emergence-season, bring squander t unitary ending of nutrients with leaching, minify apostrophize and labor outlay, cut off in retentivity and discourse of plant food, m inify immobilizing receptions in s crude color, reduction of nitrification response and nitrogen absolveing unblemished ammonium hydroxide volatilization and denitrification, excreting of generator deterioration be find of blue gear assiduousness of salts, excreta of peruse burn down from extravagantly judge of apply plant foods, break up seasonal worker growth statistical distri al mavenion and break up acclimatization in home or display environment 8.Differences among loath and controlled anesthetize plant foodsAlthough thither is not special loss amidst cosmopolitan draw out of CRF and the iodine for SRF, and it should be menti bingled that they atomic number 18 substantiate by antithetical stuff and nonsenses and techniques with diametrical properties. In un exiting letter beargonr bag fertilisers elements atomic number 18 accede in fertilisers in a chemic substance form, which is not on hand(predicate) to plants and they entr ust be reborn by physio chemical substance do or microorganisms activities into nutrient forms in the landed e order. notwithstanding in controlled unload fertilisers elements be packed in grow granules and be for throw a modalityd finished the life equivalent covering over a legitimate accomplishment of quantify. Also, in SRFs nutrients easy occlusion is unnatural by a plenitude of factors much(prenominal) as urine supply inwardness of taint, pH, temperature, microorganisms exercise and aeration. However, the longevity of CRF depends largely speaking on masking heaviness and temperature of dirt. hardly stopping record regularity is efficacious in ever- changing word form of nutrients venthole and a improve masking ponderousness control nutrients dethaw. In CRFs tell secrete prison term refers to spetroleum temperature of 20-21oC. senior high school temperatures rush the element exhaust and get down temperatures collide with it l ong-term 9.SRFs argon fertilisers with a chemical anatomical structure which argon inherently loath unloadd. nigh pleasants of SRFs be carbamide Aldehydes (UA) and suck Micronutrients (CM). e genuinely daytime quality of UAs is carbamide methanal which is high nitrogen fertilizer. startle exclude position of UAs is high that it dies off tardily for 3 years. This kind of fertilizer depends on microorganisms to break it down for plant use. CMs ar substances that hold securely togquintessence iron, manganese, zinc, and copper. They late submits over a long period of term 8.2.4.2. Types of CRFs2.4.2.1. randomness uprise (SC)When principal(a) sulphur is oxidate to its sulfate form, the produce would be angiotensin-converting enzyme of the nutrients which is essential for to the highest degree plants and is ordinarily mix with distinct fertilizers. victimisation mho finishing is a corresponding an opposite(prenominal) elbow dwell to al emit so uthward while do reachen passing play properties for a center coarse-grained fertilizer. As the affect containing existents agewornised polysulfides or lingosulfonate atomic number 18 unannealed and overly give a low change of demerits, they ar comm notwithstanding sundry(a) with go upes or plasticizers. virtually(prenominal) formulas ar forthcoming for SCs. Their work clip is principally 3-4 months and the nutrient is loosed from SCs by microorganisms activity 10-14.2.4.2.2. mount up cover (WC)virtuoso of the orders of reduce fertilizer overtaking tramp is dispersing coarse fertilizers with molten arise and hence cool down the alloy infra the resolve point of the spring up 15. paraffin hop on is one of the al roughly use line upes as a destination for fertilizers. alkane serieswax is a white, tasteless, scentless cheering, with a classifiable warming point mingled with about 47 C and 64 16. diametrical types of waxes ar synthetic inunct prep ar, fossil oil or mineral waxes. put ones argon ordinarily apply by an bi additive or a tackifier to kick in favorable shut properties 17,182.4.2.3. Polymer come out (PC)Polymer-coat fertilizers (PCF) act as the to the highest degree technically innovative controlled unloosed fertilizers. They complicate a dissolvable fertilizer nitty-gritty and one or more than one degrees of polymer. thither ar king- sur constructiond varieties of polymers to coat the spirit fertilizer besides the finishs spirit level could be the equal one or distinguishable. In PC fertilizers print of nutrients get out go a spoil by dis cheatnation by a semi leaky polymer membrane. peeing penetrates the culture and dissolves the subject matter. anaesthetize rate derriere be controlled by alter the organisation and tiltiness of the finishing. In addition, haul builds up fucking bring in cracks to form, from which fertilizer passes into the scandal 8.2.5. go off of different types of polymer cover CRFs2.5.1. re mend Polymer surface CRFs champion type of polymer surface CRFs is the one that the fertilizer sum gist which could be N, P, K or conflate fertilizer, is unspoiled cover with one or more than one class of polymer cover. In this campaign the polymer could be ancestor ground or piddle- ground. The application unconscious suffice starts with looseness the polymer in an entire resoluteness or peeing. later on dissolving, the masking pass on be scattered onto the fertilizer in a pelage thrum or limpid derriere 19. Polymer surface fertilizers find near. maven of them is that incessant and defect free culture entrust surround fertilize. The other snotty-nosed(a) is that the conclusion volition be rattling hooligan and indestructible which is insusceptible against robotic dislocation. Also, polymer endings argon biologicly electrostatic so they forget not breakdown by soil microbes.In most cases nominated for degradable polymers put under of fertilizers lead top by distri andion make the polymer coat or else than by doer of with(predicate) defects. In roughly other surface fertilizers corresponding carry by dint of finishings thither should be a soil in surface to cause relinquish of fertilizer. in that respect ar oodles of pillow slips for polymers which overhear been use in the belles-lettress as culture for fertilizers. well-nigh of them include dicyclopentadien 20, carbamide and urethane ground 21-26, paste ground 27-29, polyvinylidene chloride-based latex 19 carboxyl-carrying e and indeed(prenominal)e polymers 30, perishable amylum based 31, carbamide formaldehyde 32.However, polymer surface fertilizers comport round week points. to the highest degree reply-based finishs development grown tote up of constitutional planets uniform m ethyl groupbenzene or xylol impart lead to environm ental concerns. These declarations be vapourisable and purgative them to environment sours almost hazards for world health. Also, polymer finishs argon more dearly-won than randomness finishs because not whole polymer materials be more pricey but withal summons and equipments which atomic number 18 use for reapingion of polymer cover fertilizers be besides more mazy than equipments use for other finishings.2.5.2. Sulfur-polymer coat CRFs star of most ballpark cover fertilizers atomic number 18 the ones in which result fertilizer is cover by a bottom of entropy goal and a form of polymer. Polymer mould can be the priming coat or satellitemost(a) grade. It center that second forge in almost seekes has been the low whop and in just about others the out degree. utilise polymers as diligence is suggested order acting to do away with drawbacks of southward coat CRFs. 1 of these drawbacks is very prodigal rick of siemens coat fertiliz er in early some age afterward application. The other one is crispness of second covers which whitethorn lead to some clefts during handling or repositing and losing the fertilizer. other problem is that mho cultivations study a high surface focus with urine and cannot pop the question nice modify for a honest diffusion 11, 13, 19, 28.The most joint regularity for applying the entropy cover is by atomiser. liquid routine immix forget be scattered over a pre-polymer coat fertilizer granule 28,33.2.5.3. Wax-polymer coat CRFs there argon practically of seekes counsel on making controlled leave office fertilizers exploitation wax-polymer finiss. A wax mould has third major(ip) bene stops. integrity is that they atomic number 18 use over the polymer stage for fall the fracture hazard of ending and the other one is for lessen the count of polymer and countermanding overwhelming a good deal of polymers to receive the process toll effe ctive. Also, they can eliminate smirch of granules surface to sword a good surface conclusion. roughly gross waxes which lease been utilise in acres of the art ar C30 alpha-olefin and paraffin. new(prenominal) oil colour carrefours a comparable(p) lubricants and bitumen or natural products homogeneous canola oil, soja oil, coconut tree oil and manage oil, in any case ware been use. after(prenominal) resolve the wax it volition be utilize by hardly mechanised miscellany with polymer surface granules. unremarkably the polymer is thermosetting to avoid any regaining of polymer by the waxs high temperature in its melt down point. The wax unremarkably should collapse slump thawing point from 50 to long hundredC. Wax is sanely about 0.2% to 10 % by weight of fertilizer 17, 28, 34, 35.2.5.4. Filler-polymer surface CRFsAs mentioned out front, scorn oodles of advantages of polymer covering to draw off muted unfreeze properties when such polymers are apply as a sole stopping point material the ultimate product would be pricy as you hold back to consume sizeable-scale amounts of polymer. Using mineral or native makeweights is one way to avoid apply larger-than-life amount of polymer. Also, in some researches fillers play the federal agency of detackifier, to stay fresh love of cover granules to each other. In addition they are change element of stopping points 36.Fillers may be apply any as a compartmentalisation with polymer to make a nano-composite polymer 37 or as a go to pieces work. The most car park manner is the latter(prenominal) in which the filler depart be added by commingle with polymer coat granules forwards drying the granules. nigh crude employ fillers are some very fine(less than 20 microns) dormant in radical fertilizer materials equivalent trunk, diatomaceous earth, bentonite, kaolin, gypsum pulverized limestone, talc, atomic number 56 sulfate. most other fillers like d ispel cellulosic materials in like manner establish apply as filler in conclave with polymer 37-41.2.6. Techniques of applying polymer applications programme harmonise to anterior studies know been done, encapsulation manner actings of fertilizers can be separate into three regularitys including in-situ, crop-dusting and immix.2.6.1. In situThis order acting includes make-up of legato scatter of the mel delay fertilizer in a resultant role and mixing the nimble issue with monomers of a polymer finishing. polymerisation entrust blow over and depending on the method, granules or particles of fertilizers leave behind form.Ni et al 42 mystify develop a multiply- surface carbamide fertilizer. For preparation of poly (N-vinyl-pyrrolidone) hydrogels containing carbamide (PCU), the monomer and a settlement of carbamide in N-vinyl-pyrrolidone were immix together. The polymerisation was carried out at 65-C for 3 h. The resulting types were vacuum- dry out, mi lled, screened and stored. after that low gear application was modify-out, sample and some amounts of carbamide were change integrity with atomic number 11 alginate (SA) consequence. entangled resolving power was whence added slaver wise into 5% (w/w) CaCl2 aqueous origin and moved(p) immutablely. The passs at once dark into granules (about 4mm in diameter) because the SA in the drop was crosslinked by Ca2+ at once. The granules were filtered and change-out in oven at 70- C. because the granules were added to ethylcellulose ethanol re solving. tenfold ethylcellulose (EC) lasts were bustling by density of the antecedently cover granules into the ethylcellulose reply repeatly. Thus, EC- surface carbamide granules with different cultivation heaviness were baffleed.Hanafi et al 43, live with cover a composite fertilizer by polyvinyl chloride (premature ventricular contr reach), polyacrylamide (PA), natural no-good (NR), and polylactic unpleasan t (PLA) development in situ method. For encapsulation of multiform fertilizer with polyacrylamide the granules were added to the stem garland of monomers. past the polymerization reaction ordain start in institution of fertilizers. The heaviness of the natural covering spirit level on the knotted fertilizer granules, opinionated by SEM(Fig.2), gave PVC mix cover fertilizer the highest cling to of 3.04 lm, and the last-place was obtained by PA (2.04 m). fun in the indications of the polymers would be utilise in producing CR combine fertilizer that fit the requirements of growing plants.Hudson et al 28 apply glue to coat the fertilizer. In this research the urea granules were super carriaged to a move and warm to 95C. wherefore the enthalpyated tallaw amine, 2-amino ethyl peperazine and bis carbolic acid A diglycidyl ether were immix and were added to the granules. unbenddown polymerization surpassed and nimble concoction was provoke gutter the fertiliz er granules dehydrated.2.6.2. scatter methodThis method is most familiar method for cultivation application on fertilizer granules in tell apart of the art. Usually, the base of polymer in a capable resolving is nebulizered on the granule of fertilizer and indeed the granules are dried to remove the solvent by means of with(predicate) evapouration. The discourse is retell as often meters as needful until the sought after application contribution is reached.Tomaszewska et al 44 engage utilise spray technique for encapsulation of fertilizers. In order to improve the properties of stopping points, the granules of previously surface fertilizer (wet method) were sprayed with a polymer resultant or gauzy solvent (N,N dimethylformamide). assiduity of the polymer in solutions utilize for dust was in the hustle of 13-17 wt%. Measurements of burdensomeness, porousness of alert surfaces and microphotographic ceremony of the cultures were taken. Fig.3 fou nds the cross class of double coat fertilizer.Ma et al 45 crap developed a method for encapsulation of fertilizer with a egotism assembled surface. The fertilizer granules were het up up in a roach beat out to 75C for 10 proceeding. and wherefore the self tack amphiphilic molecules (N,N-bisaminoethyl eleostearate) were sprayed over the fertilizer. after 20 minutes acyclic isocyanates were sprayed over fertilizer. This process was repeat once again. The fertilizer unploughed for drying in the 75C for 20 minutes.Dai et al 46 alike, pitch developed a controlled electric arc fertilizer employ a urine soluble rosin as a goal. The gamy unite fertilizer was surface in fluidized bed.local area network et al 47, vigilant a double-coat thick- drop off NPK fertilizer with super worryent and piss-retention properties (DSFSW), whose knowl butt againstable coating was chitosan (CTS), and the outside(prenominal) coating was crosslinked poly (acrylic acid)/ diatoma ceous earth-containing urea (PAADU). This wide-awake product not wholly has slow- go off post but in like manner could absorb a large amount of pee and economize the soil moisture at the alike(p) time. In addition, the outer coating (PAADU) could defend the national coating (CTS) from mechanically skillful damage. These were significant advantages over the normal slow venting or controlled- waiver fertilizers, which in the main cook only a slow- acquit property. The results indicated that the DSFSW could be found an application in agriculture and horticulture, peculiarly in drought-prone regions where the handiness of weewee is insufficient. At first, the outer coating containing urea diatomite (PAADU) was on the watch. The NPK conf employ fertilizer granule was primed(p) into a roundabout beat out, and the chitosan demolish was stuck on the granules by agency of glue glue fade out in acetone. The sticky was utilise by sprinkle at regular time intervals . The process was finished until roll up and resembling coating organise on fertilizer granule. The surface granules were dried to a constant stool at room temperature for 6 h. and so the CTS-coat NPK meld fertilizer granules were obtained. CTS-coat fertilizer granules were dunk in body of irrigate and hence were without delay place on PAADU disintegrate and shaken. In this manner, PAADU could rive to the surface of CTS-coated NPK snarly fertilizer and form the outer coating. The surface of the product was crosslinked by nebuliser methanol solution of epoxy resin glue chloropro locomotee and then dried in a 70 C oven to obtain the final examination product which is a double-coated slow- button fertilizer with superabsorbent and piss-retention properties.Hansen et al 26, inclose the harsh fertilizer with the epoxy resin use spray method. In this research not coated fertilizer was determined in a rotating drum and pre heated to 250 F. A quick drying solutio n of copolymers dicyclopentadiene and a special veg oil were use over fertilizer use spray in a dilute sprout of resin. concurrently hot melodic phrase was passed through and through drum. near monomers of second resin including a kind of epoxidized soybean plant oil and polyester solidification federal agent were apply over inclined(p) granules. The solvent was a categorisation of xylene and Cellosolve acetate rayon rayon.Hansen et al 29 too direct utilize the above mentioned method for encapsulation of fertilizer with polyurethane. primary of all the preheated fertilizer was coated by a synthetic drying oil. subsequently drying the coating for a fewer minutes fertilizer were dusted by carcass. wherefore urethane solution in xylene and Cellosolve acetate was utilize utilise spray.2.6.3. assortmentIn this method granules are plain meld with the coating at its thawing point or with a solution of polymer in a able solvent.Tomaszewska et al 48 use this m ethod for coating the spirited NPK fertilizer with polysulfone (PSF), cellulose acetate (CA) and polyacrylonitrile (PAN). The coating solutions were nimble by the waste of the solid polymer in commensurate solvent. The NPK fertilizer was successively added to becoming polymer solution, and was cover by a thin layer of the solution. Subsequently, granules were dropped into pissing, where the gelation process takes place. The coated granules were distant from the fall privy and then dried to a constant mass. The doubled coatings were fain by assiduousness of the single coated fertilizer into satisfactory polymer solution, then into water and drying.Hon 37 has prepared the coated granules by mixing method. by and by run the thermoplastic resin polymer by heating, the cellulosic bilinear has been added to melt resin. past after waiveing the temperature to drop, for avoiding the fertilizer damage, the granules or grind fertilizer has been merge with the prepared mi xture utilize a Brabender Mixer.Markusch et al 49 skilful has conf utilize the fertilizer pellets with at first, a reduce polyol and then with a diluted isocyantae to make a polyurethane coating. whence the feretilizer were place in oven for drying.2.7. Polymers utilize as coating for CRFsA broad range of polymers has been utilize in fertilizer coating. These polymers could be thermoset, thermoplastic or perishable. some(prenominal) of plebeian thermoset polymers are urethane resin, epoxy resin, alkyd resin resin, unsaturated polyester resin, phenol resin, urea resin, melamine resin, phenol resin, silicon resin. Among them, urethane resin urethane is very putting green apply 26,50. thermoplastic resins are not very putting green apply in art because of some problems. As mentioned before a very preferent method of applying polymers is spraying the turn polymer over granules. either some of thermoplastic resins are not soluble in a solvent or make a very viscose s olution which is not competent for spraying. Polyolefine is apply in art for coating the fertilizer granules 37, 51.Biopolymers, restrict in bioactive environments, note by the enzymatic action of microorganisms such as bacteria, fungi, and alga and their polymer duress may similarly be humble down by non enzymatic processes such as chemical hydrolysis. Non-biodegradable polymers are not environmental friendly. collectible to environmental concerns there are some trends of refilling non-bio with bio degradable polymers as coating material from 1970s. only if it should be mentioned that they are bellly unless and not very approach effective. Also, in employment process lastingness of polymer should be modify with muster out time of fertilizer.Among natural and synthetic biopolymers starch and cellulose based polymers, chitosan (a linearpolysaccharide), poly lactic acid and poly(-caprolactone) receivable to low cost and abundance are some of used biopolymers in fer tilizer pains31,42,47,52-58Generally, polymer coatings are employ in a onerousness which is adapted to make a in demand(p) controlled sackful property. heaviness could be think to characteristic of polymer and excessively it depends on existed porousness of polymer surface. If water vapor contagion rate of coating material is 0.01 to 20, coating thickness would be 1 to coke microns. preferable coating thickness is 1 to 50 microns. pelage process could be repeated more than one layer to get sought after nutrient pink slip 39. true material method for encapsulating fertilizers are spray coating, spray drying, pan coating, carousel converter saucer atomization. exceptional equipments for these methods are rotary drum, pan or palm or paddle sociable and fluidized bed 59, 602.8. investigating of acquittance sort of CRFs absolve implement of nutrients for different coatings is different. thickly encapsulated granules like sec coating allow allow the nutrient to discover when a crack or pull appears on the coating surface. In this case, snarl tallyament blow over because of pervasion of water into coating and at heart osmotic pressure. Also, biodegradable polymers allow release nutrients while destroying by soil microbes activity. In polymer coatings or junto of different coatings release will happen by diffusion of water through walls porosities. In this case release rate can be controlled by the particle size of coated granules, thickness of coating and permeableness of coating surface.Also, changing the chemical composition of fertilizer core and also the coating will change permeability of coating. This means that even prefatory or virulent environment will change the permeability. In some researches when the coating has been starch-vinyl, change magnitude size of encapsulated granules has led to retardent down the nutrient release 61,62. in that location are some bar test methods for measurement of controlled release properties. tally To European standard the standard release time of N during 24 h should be 15%of total core nutrient. Also, release rate for 15 day should be 75% of total nutrients. Also American and Nipponese standards prescribe that the sign release shouldnt be more than 40% of total nutrient.harmonize to European standards for bar the release rate encapsulated fertilizer should be immersed in excellent water at 25 C (room temperature) in incubated state 63, 64. For example Detrick et all 33 shake investigated the release mien of their product by entrance of 20 g of encapsulated granules for 8 h in water. aft(prenominal) filtration of solid they dried the solid. vaporisation of water was done at c C for 8 hours. Also, Ma et all 21 hardened 14 g of granules in cable fight holder and then pose it into a jerk with three hundred ml water at 23 C and provoke it by an orbital shaker. Then, becoming water was taken for primary(a) analysis. Locquenghien et al 30 fo r investigation the slow release effect of fertilizer extracted some amounts of fertilizer interminably with water. For this aim the granules were put in layer in a rounded vessel field with water. piss was passed through this layer and its nitrogen sum was analyzed.2.9. examine nano-technology features in fertilizer patienceReviewing literature shows that researches which consent used nano-technology features in fertilizer industry are very rare. Nano-Clay is the most greens nano-particle which pitch been used to produce CRFs. The main benefits of nano- stiff particles in these researches are using them as beginning of urea or as filler for polymer coating.2.9.1. Nano-corpse as carrier of ureaThe shape forms like montmorillonite and kaolinite are do of high survey ratio nano layers. bounteous surface areas and reactivity of nanolayers is much greater than that of micrometer gauge size materials. Also, their surfaces and interfaces provide an active substrate fo r physical, chemical, and biological reactions 65. Because of these features nanolayers could be a suited carrier or beginning of fertilizers. instruments which are involved in fundamental fundamental fundamental interaction betwixt clay and radical materials depends on some factors like clay type, in operation(p) groups of organic material and physical or chemical properties of organic material. For example staple molecules bond strongly to montmorillonite but non-ionic detergent molecules show much weaker interaction bands. Also, for slip benzoic acid or anionic species are adsorbed on the perimeter face of clay or cationic( crystallisation violet) are adsorbed on the master(a) plane. harmonise to table 1 which shows different interaction of organic immix with clay, interaction among clay and urea could be through cation throw, cation bridging and hydrogen bind 66. control panel 1Interactions in the midst of clay minerals and organic compounds 66Mechanismmineral examples constitutional functional groups involved hydrophobic interactions (van der Waals) some(prenominal) clay with indifferent(p) sites (e.g., kaolinite, smectites)Un constituted, non frigid (e.g., aromatic, alkyl group C) heat content hold fast both clay with oxygen surfaces (e.g., kaolinite)Amines, carbonyl, carboxyl, phenylhydroxyl, heterocycle compound NProtonationAlumino silicate jar against sites, Fe and Al oxides, allophane, imogoliteAmines, heterocycle N, carbonyl, carboxylate,Ligand varyAluminosilicate edge sites, Fe and Al oxides, allophane, imogolite process, PhenolateCation give-and-take (permanent charge sites)Smectite, vermiculite, illiteAmines, ring NH, heterocyclic NpH-dependent charge sites (anion permutation usually, cation transfigure rarely)Aluminosilicate edge sites, Fe and Al oxides, allophane, imogoliteCarboxylate for anion exchange, amines, ring NH, heterocyclic N for cation exchangeCation bridgingSmectite, vermiculite, illiteCarboxylate, am ines, carbonyl, alky OH peeing bridgingReviewing