Characteristics Of Modified Biochar-Based Fertilizers And Its Application In Production

With the rapid development of agriculture in China,it is a common phenomenon that more and more agricultural and forestry wastes were produced which were most abandoned or burned.Crop straw as the main source of agricultural waste has attracted more and more people’s attention about its uses.Biochar is one kind of carbon material which is highly aromatic and difficult to decompose,the application of biochar in field crops could not only reduce the leaching loss of soil nutrients,improve the structure of soil,but also achieve carbon sequestration,increase crop yield and improve the quality of crops.Biochar has the characteristics of porosity,large surface area and surface charge and it also has some ability of holding nutrients,so the biochar could be used as carrier of fertilizers and then mix with chemical fertilizer by certain process to produce the biochar-based fertilizer.In this paper,we chose wheat straw as experiment material,then it was modified and prepared to make two kinds of modified biochar-based fertilizer,after that we used the methods of SEM and XPS to analyze the micro-structure of these biochar-based fertilizers and compared the application results of modified fertilizers in wheat and green pepper.The main results are as follows:(1)Compared with conventional biochar,the semi-modified and modified biochars after phosphate activation have more surface functional groups and the surface area of biochars are increased.The surface nutrient distribution of modified biochar-based fertilizers is more abundant than conventional biaochar-based fertilizer and also the nutrient slow-release is more obvious than compound fertilizer or conventional biochar-based fertilizer;(2)The experimental results of application of biochar-based fertilizers on wheat show that:with the topdressing in wheat,there is no significant influence on nutrient absorption and yield index of different fertilization treatments;under the condition of without topdressing,the fertilization treatments reduce nitrogen application by 95%,although there is no significant difference among different treatments,the nitrogen partial factor productivity of them is higher than topdressing treatments by more than one times.Therefore,the biochar-based fertilizer can reduce the application amount of fertilizer so as to improve the efficiency of fertilizer nutrient under the premise of guarantee the wheat yield.(3)The experimental results of application of biochar-based fertilizers on green pepper show that:with the same application amount of biochar-based fertilizer(37%of the total nutrient)and compound fertilizer(45%of the total nutrient),the semi-modified biochar-based fertilizer(BF2)and modified biochar-based fertilizer(BF3)can significantly improve the pepper yield by 16.6%and 18%respectively than the CF treatment;the soluble protein content in BF2 treatment was increased by 18.24%than that of CF;BF3 treatment could significantly decreased the content of organic acid by up to 13.70%than CF treatment;three kinds of biaochar-based fertilizer treatments can significantly reduce the nitrate content in pepper fruit compared with the compound fertilizer treatment,so as to improve the safety and quality of vegetables.