Study On The Preparation Technology Of Machine Applied Granular Fertilizer With Water Retention Function

China is a big agricultural country.Its agricultural production has a long history,huge scale,and many employees.Northeast and Huanghuaihai region are the main grain producing areas in China,where they are still faced with the problems of low mechanization degree,water shortage and drought.On the one hand,with the development of the times and the shortage of rural labor force,mechanized fertilization has become an inevitable trend in history,and the northeast and Huanghuaihai areas are flat,which is very suitable for agricultural mechanized production.At present,fertilizer application machinery has been gradually popularized in these areas,but there is a lack of corresponding mechanical fertilizer application,so it is necessary to develop fertilizer products and processing technology suitable for mechanized fertilization.On the other hand,the water resources in these areas are relatively scarce,and agricultural water accounts for the majority of the total water consumption.At the same time,irrigation projects are time-consuming and labor-intensive,and it is necessary to take corresponding measures to reduce the threat of drought.In response to the above two problems in agriculture in the Northeast and Huanghuaihai region,the purpose of this project is to prepare a mechanized fertilizer that meets the nutrient requirements of crops in the Northeast and Huanghuaihai areas and has the functions of water and fertilizer retention.This experiment is divided into three parts,the main research contents are as follows:In order to meet the demand of mechanized application,the product should be granular and have high strength to reduce the loss in production,transportation and application.At the same time,the granulation process should have high granulation rate to reduce the cost.In this experiment,the superphosphate and diammonium phosphate produced by Zhanhua company were used as raw materials for disc granulation experiment to explore the influence of different granulation process conditions and binders on the particle properties of products.According to the experimental results,the best binder and optimal process conditions were established.Under the optimal conditions,the particle strength of products was more than 40 N,the granulation rate was more than 90%,the disintegration and falling time in water was less than 15 min,full Sufficient mechanized application requirements.In order to solve the problem of drought and water shortage in Northeast China and Huanghuaihai region,the super absorbent resin was prepared as water holding agent to reduce water loss and enhance water holding capacity.In this experiment,humic acid and clinoptilolite,which are cheap and easy to get in Huang Huai Hai area,are selected as raw materials.They are innocuous and harm Less.They are good for the growth of crops.The preparation of superabsorbent resin with aqueous solution is simple.The water absorption ratio of the prepared superabsorbent resin is 2076.6 g/g,and the water absorption ratio of0.1%-1.2wt%salt solution（Na Cl,NH₄Cl,Na₂CO₃）is still 97.38-379.32 g/g.The water absorption capacity of the product is reduced with the increase of temperature,and it has good water retention capacity at room temperature.After repeated use for 10 times,it still has 50%water absorption capacity.Superabsorbent resin and fertilizer particles are combined in different ways to reduce agricultural production steps and reduce costs.The study combined the superabsorbent resin and fertilizer by chemical crosslinking and physical coating respectively.In the chemical crosslinking method,we need to add different quality of diammonium phosphate,and the water absorption capacity of the prepared water-retaining fertilizer was 144.8-1048.4 g/g.Through the reaction process is easy to control the reaction conditions,the fertilizers carried are limited.In the physical coating method,the superabsorbent resin outer film only accounts for 9%to 18%of the total mass,and contains more nutrients,which can meet the needs of crops and is suitable for application in agriculture.When the coating amount is 12%and the drying temperature is 105℃,the strength of the water-retaining machine-made granular fertilizer prepared by the coating method reaches 50.71N,and the water absorption rate is 98.7 g/g,which can meet the requirements of mechanized application,improve the soil water retention capacity and achieve the versatility of machine fertilization.