Development Of Economical Coated-ureas And Investigation Of Crop Effect

Capsule slow controlled release nitrogen is an important way and method to resovethe low utilization ratio of nitrogen fertilizer.The research and manufacture ofeconomic type of slow controlled release nitrogen is being paid more attention.Thetectorial object of this research is urea, probed the molding techenology ofcoated-material by screening the material of coated-material and combining-reagentand the assembly concentration, and then develop two sorts of coated ureas.Useingwater solution,volatilization test,soil column leaching and potted trial to research thespeciality of coated ureas,to support the use on agricultureThe main results were following:(1)Through the binder concentration of screening and allocate, economical coatedmaterials selected with binder matched stack of both matched stack, studies theinfluence of coated urea properties. Preliminary determine the quality of urea andcoated materials ratio of1:1，Binder HY dilution to5%CX50%, suitable for binderconcentrations of urea coated molding. Based on the practical three economy wereslow relaese urea production formula.（Namely coated urea no.1,2and3）(2)Through the capsule process parameter selection test，sure a coating machiningcoated urea speed for55～60r/min，temperature for65。C，time for1.33h is optimumtechnological conditions.(3)The water solution was used to measure the initial and differential dissolved rate.The result show: the initial dissolved rate of the three coated ureas were38.69%,29.43%,48.13%,respectively. The differential dissolved rate of the threecoated ureas were2.53%,2.6%,2.35%. The result show: the order of initial dissolvedrate was No3Coated Ureas> No1Coated Ureas> No2Coated Ureas. The order ofdifferential dissolved rate was: No2Coated Ureas> No1Coated Ureas> No3CoatedUreas. Influence of differential dissolution rate of main factor is adhesive ratio of typeand coated materials.(4)Using soil cultivates experiment to determine the ammonia volatilization of coatedureas in soil.It turns out that the nitrogen accumulation volatilize quantity of first,second, third coated ureas and ordinary urea are21.02mg、19.73mg、27.77mg and38.73mg in30days. Compared with the ordinary urea in the same nitrogen whichdispose of U, the lose of ammonia volatilization and total nitrogen reduce observably.And it also can reduce the speed of ammonia volatilization, the fastigium of ammonia volatilization of coated ureas is lag behind the dispose of ordinary urea.(5)Using soil column leaching method to evaluation the amount of nitrice-nitrogen,ammonium-nitrogen and total nitrogen leached of coated ureas，and evaluation of theeffects of the soil’s pH. It turns out that in the condition of apply the same nitrogen,compared with the ordinary urea, using the coated ureas can reduce nitrogen leachingeffectively. And the accumulated leaching quantity of coated ureas’s nitrogen is lowerthan ordinary urea, it means the coated ureas has the capacity of nutrient preserving.In the soil column leaching experiment, the nitrogen of soil in upper and lower levelsare all increase after leaching, but not in the same level, pH of the soil that leached bythe ordinary urea is increase the most.(6)The result of potting experiment of coated ureas means, the three elaborate coatedureas are all conducive to increase the agronomic and yield traits of crop, so that crophigh-yielding. The cabbage CU, CU2, CU3higher than U14.76%,21.15%and5.49%.The above ground part of wheat U, CU1, CU2, CU3higher than CK6.16%,16.93%,31.10%and18.04%. The under ground part of wheat U, CU1, CU2,CU3higher than CK12.16%,36.38%,24.42%and31.36%.