Study On The Characteristics And Efficiency Of Biochar-based Compound Fertilizer

Chemical fertilizers play an important role in increasing crop yields and are widely used in agricultural production activities.Along with mankind pursues crop production,the excessive use of chemical fertilizers blindly brings a series of agricultural pollution,which already threat the development of green agriculture around the world.Biochar is a nutrient-rich,loose and porous material made by high-temperature anaerobic carbonization of crop straws and forestry wastes.It can be used to improve soil quality,as well as prepare slow-release fertilizers by combined with chemical fertilizer particles.In this study,biochar and chemical fertilizers were used as raw materials to prepare biochar-based fertilizers.We have investigated the basic characteristics of biochar-based fertilizers,and evaluated the nutrient release effect of biochar-based fertilizers.Hopelly the result can expalain the effect and technical basis for the application of biochar-based fertilizer in agricultural production.The main results of the study are as follows:（1）Biochar has a rich pore structure and can be used as a carrier for biochar-based fertilizers.The combination of chemical fertilizer particles and biochar makes the structure of biochar-based fertilizer appear disordered,however,as the amount of biochar adding,the disordered structure of biochar-based fertilizer improves as well,and along with the pore volume and size increase.The biochar-based fertilizer contains functional groups similar to those on the surface of biochar,and is less affected by the amount of fertilizer added.In the biochar-based fertilizer,as the amount of biochar adding,H/C,O/C and（N+O）/C increase,which weakens the aroma of the biochar-based fertilizer and enhances the affinity of the biochar-based fertilizer.（2）The biochar-based fertilizer has an adsorption effect on nutrient separators.Compared with the fertilizer,the nutrient release duration is longer,and the slow-release effect is more obvious;the release rate and amount of NH₄⁺,P,and K in biochar-based fertilizer treatment are lower than HF treatment.（3）The results of simulation experiments under different humidity,temperature and p H soil environments show that the slow-release effect of biochar-based fertilizers is significant.when the soil water holding capacity is high,and there is no obvious difference between the treatments;as the soil temperature increases,the biological damage are significantly damaged The slow-release effect of carbon-based fertilizer is the worst when the temperature reaches 30℃;in neutral and acid soils,the nutrient release effect of bio-carbon-based fertilizer is ideal,and the release rate and release amount are more stable and better than HF.In alkaline soil,the release effect of biochar base fertilizer is not as good as chemical fertilizer.（4）Biochar based fertilizer can effectively be a supplement the content of available nutrients and organic matter in the soil and reduce the loss of soil nutrients.Biochar-based fertilizers can promote soil enzyme activity.Compared with HF treatment,biochar-based fertilizer can increase the activity of soil urease by 5.56%～33.33%;increase the activity of phosphatase in soil by 6.38%;have no significant effect on the activity of peroxidase;increase the activity of sucrase by 9.09%～26.08%.（5）The effect of single application of chemical fertilizer on the comprehensive traits of crop growth is better than that of single application of biochar,while the application of biochar based fertilizer on the promotion of the comprehensive growth traits of crops is better than that of single application of chemical fertilizer.Moreover,biochar based fertilizers can improve the soil conditions around the rhizosphere,which is conducive to the growth of crop roots and promote nutrient absorption of crops.（6）Under the same chemical and other nutrient inputs,the biochar-based compound fertilizer can improve the nutritional quality of plant compared to chemical fertilizers.Considering the effect on quality,the carbon-based compound fertilizer with a biochar ratio of 40%is a more suitable ratio.（7）Chemical fertilizers will destroy the original micro-biodiversity in the soil.The application of biochar in the soil can improve biodiversity,and the addition of chemical fertilizers can reduce the destruction of biodiversity.According to the amount of biochar added,the biochar base fertilizer with 30%carbon content has an ideal balance and 50%pure biochar addition has similar biodiversity effects.