Study On The Organic-Inorganic (Minerals) Controlled Release Materials And Their Controlled Release Mechanism

In this paper we us organic—inorganic (mineral) materials to modify nitrogen fertilizer, phosphate fertilizer, potassium fertilizer and microelement (Zinc) fertilizer, and to prepare controlled release fertilizer. This study belongs to the across front item among soil fertilizers, clay minerals, agriculture balance fertilizing principle and chemical engineering controlled release technology. It has bigness stratagem significance not only for agricultural continuable development, but also for environmental protection, the high efficiency using of resources etc. which use organic-inorganic (mineral) controlled release materials to develop controlled release fertilizers. And it has expansive application foreground and extending exploiture value. In this paper we proceed with organic-inorganic (mineral) controlled release materials, and adopt modern spectra analysis testing technology to study and clarify its controlled release mechanism. It will offer scientific bases for the manufacture, extending and popularization of controlled release fertilizers.It makes several major conclusions as follow in this paper:(1) The aspect in slow release nitrogenous fertilizers:We use modified clay minerals to treat ammonium bicarbonate and urea, and prepare a batch of slow release ammonium bicarbonate and slow release urea. The pot experiment shows that slow release ammonium bicarbonate and slow release urea can increase biomass of water spinach greatly than normal nitrogenous fertilizers. The structure analysis and the study of spectra property of slow release ammonium bicarbonate and slow release urea shows that after being modified, the molecules of ammonium bicarbonate and urea can enter the interlayer or cage of clay minerals or zeolite. The molecules of ammonium bicarbonate and urea can make the weak covalent bond with the surface of structural layer which is stronger than hydrogen bond. Thisweak covalent bond increase the stability of ammonium bicarbonate and urea, and it make modified nitrogenous fertilizers possess controlled release capability, and enhance the use efficiency of N.(2) The aspect in promoted release phosphate fertilizers:Three types of new high-efficiency phosphate fertilizers were made when additives of certain proportions were added into ground phosphate rock. Chemical analyses showed that their soluble phosphorus content decreased than superphosphate. Pot experiment showed that, under equivalent weights, the new fertilizers increased their efficiency by a large margin than superphosphate. Researches on their structures by means of XRD and IR spectrum discovered that their crystal structures undergone changed considerably, improving their activity and preventing the fixation of available phosphorus in the soil. These changes, consequently, greatly improved the bioavailability and became the main cause of the increase of biomass. The changed forms of phosphorus after additive treatments strengthen the ability to resist fixation. The assortment of different forms of phosphorus has formed a reliable "column orientation balance" which is better adapted to the needs of crops and will enhance the fertilizer use efficiency. Deep researches into the properties characters and characteristics of these effective elements and proper production conditions will be greater significant to develop new, high efficiency phosphate fertilizers and improve phosphate fertilizer use efficiency.(3) The aspect in long effect potassium fertilizers:We use organic-inorganic (minerals) to modify chemical potassium fertilizer, and prepare long effect organic-inorganic (minerals) modified potassium fertilizer. The organic-inorganic (minerals) modified potassium fertilizer possesses long effect. The pot experiment shows that modified potassium fertilizer increase the biomass of corn in second batch. X ray shows that the structure change of modified potassium fertilizer is relative to the interlayer property, the suitable proportion and the physical-chemical condition of modified materials. The IR of chemical potassium chloride fertilizer is weak. And it has a macromolecule pigmentation layer. Afterorganic-inorganic modification, the macromolecule pigmentation layer is been destroyed. While the destruction of macromolecule pigmentation layer doesn't decrease the availability of potassium. Reversal, the controlled release action of organic-inorganic (minerals) non-envelope is longer than the macromolecule pigmentation layer.(4) The aspect in inorganic (minerals) Zinc fertilizer:The mineral Zinc fertilizers were prepared by cation exchange method. The adsorption isotherms of montmorillonite and vermiculite adsorbing Zn2+ assume double "S" type, while the adsorption isotherms of zeolite adsorbing Zn2+ assume "Langmuir" type. The adsorption capacity gradation of three minerals asorbing Zn2+ is montmorillonite > vermiculite > zeolite. The result of potted plant show that the biomass of two batchs corn after using zinc fertilizer is better than CK(not using zinc fertilizer). In first batch, the biomass of vermiculite-Zn is the best, and in the second batch, the biomass of montmorillonite-Zn is the best. We also use XRD, IR, DTA and TG to analyze the crystal structure of minerals and mineral zinc fertilizers. It reveals that vermiculite-Zn can be used as quick efficiency zinc fertilizer, while montmorillonite-Zn can be used as long efficiency slow released zinc fertilizer. It is possible to use mineral to prepare control released zinc fertilizer.