Preparation And Application Of Biomass Carbon-based Coated Fertilizer

Biomass charcoal has a rich pore structure and is a high-quality soil amendment.The biomass charcoal-based fertilizer prepared by mixing biomass charcoal and fertilizer can not only improve the soil,but also effectively increase the utilization rate of fertilizer.However,traditional biomass char-based fertilizers have insufficient strength and are easily lost during transportation,and there are still problems such as too fast nutrient release and unstable nutrient release.Therefore,the preparation of carbon-based fertilizers with high particle strength and stable slow-release performance is an urgent problem to be solved.Based on this,this research proposed a new binder preparation method,obtained a binder with excellent performance,and applied it to the preparation of biomass carbon-based coated fertilizer;analyzed the coating amount and biomass carbon The relationship between the mechanical properties and slow-release performance of the base coated fertilizer,and the effect of the biomass carbon-based coated fertilizer on the growth index of pakchoi and the soil environment was studied by pot experiment.The main work and conclusions of this paper are as follows:（1）An excellent starch/PVA binder that can be used for biomass carbon-based coated fertilizers is prepared by modification.Borax and glycerin as crosslinking agent and plasticizer respectively can reduce the water absorption of starch/PVA composite film materials.In 150 m L of distilled water,control the sum of the added mass of starch and PVA to 10 g.When the mass ratio of starch to PVA is 2:3,the amount of crosslinking agent borax is 0.1 g,and the amount of plasticizer glycerin is 3 m L,The composite membrane has the lowest water absorption rate of 78%;the addition of nano-SiO₂ can further improve the mechanical properties and hydrophobicity of the starch/PVA composite membrane material,and effectively inhibit its rapid degradation in the soil.Comprehensive analysis shows that when the amount of nano SiO₂ added is 1.5 wt%,the effect is the best.Compared with no addition,the water absorption rate of the composite membrane material is reduced by 38.4%,the water contact angle is increased by89.5%,and the tensile strength is increased by 49.0%.,The soil degradation rate is reduced by 16.4%.（2）Using the binder prepared above,using biomass charcoal as the coating material,prepare biomass charcoal-based coated fertilizers with different coating amounts in a coating machine.Experimental studies on fertilizer particle size,compressive performance,abrasion resistance and moisture absorption show that its film-forming performance is 30%biomass carbon coating>20%biomass carbon coating>10%biomass Carbon coated.（3）Using indoor constant temperature soil column leaching and ammonia volatilization experiments,the ammonia volatilization and nutrient release laws of biomass carbon-based coated fertilizers with three coating amounts of 10%,20%and 30%were studied.The results showed that the total ammonia volatilization,the cumulative leaching loss of ammonium nitrogen and nitrate nitrogen of all biomass carbon-based coated fertilizers were reduced,and the larger the coating amount,the better the effect.In addition,the characteristics of the cumulative volatility curve of biomass carbon-coated fertilizer conform to the S-type equation,and the cumulative leaching loss curve of ammonium nitrogen and nitrate nitrogen conforms to the logarithmic equation.（4）Through pot experiment,the effect of biomass carbon-based coated fertilizer on the physiological characteristics and yield of Chinese cabbage was studied.The results showed that compared with conventional fertilization,the biomass carbon-based coated fertilizer can increase the number of leaves,maximum leaf length,maximum leaf width,leaf area,plant height and fresh weight of Chinese cabbage,and reduce the root-to-shoot ratio and nitric acid of Chinese cabbage.Salt content.In addition,under the condition of reducing the application of 20%biomass carbon-based coated fertilizer,the pakchoi grows well,and compared with ordinary fertilization,there is no obvious reduction in yield.At the same time,the effect of applying biomass carbon-based coated fertilizer on soil nutrient content was studied.The results show that,compared with conventional fertilization,biomass carbon-based coated fertilizers can increase soil pH,available phosphorus,available potassium and exchangeable calcium and magnesium content,increase soil organic matter content,and reduce soil ammonium and nitrate nitrogen leaching lose.