Biochar-based Se-bioenriching Technology Applied To Production Of Healthy Agro-products

With economic development and social progress,the demand for food health and safety is growing.Selenium is an essential trace element of human body,has many important biological functions,and is closely related to human health.In view of the general shortage of selenium intake in China,selenium-rich agricultural products are produced through external sources to enhance the nutritional level of selenium.Agricultural straw carbonization technology heat-decarbonized biomass waste into solid biochar and liquid wood vinegar,biochar and cultured waste co-treatment to develop soil conditioners,wood vinegar with mineral nutrients into leaf conditioning agent.Biochar can be combined with selenium-rich technology to achieve selenium-rich and nutritious production of healthy agricultural products by improving soil health and plant health,improving bio-selenium-rich efficiency,and improving soil-plant-agricultural products-food chain selenium conversion.Through the test demonstration of the selenium-rich industrial park in Zhishan,Lishui District of Nanjing,this paper finds out the feasibility and application effect of biochar-based biological selenium-rich conditioning technology in the production of selenium-rich healthy agricultural products.The main results are as follows:（1）Using biochar-based leaf surface conditioning biological selenium-rich technology,the content of selenium in agricultural products increased 4 to 5 times over the conventional level,and the main agricultural products in the park realized the production of selenium-rich healthy agricultural products.Brown rice selenium reached 0.17 to 0.18 mg kg^-1,tea selenium content reached 2.0 mg kg^-1,all reached the Ministry of Agriculture selenium-rich agricultural products industry standards;Garlic seedling selenium content of0.4 mg kg^-1,close to the natural selenium-rich areas of garlic selenium content(0.5 mg kg^-1);The selenium content of chili peppers reached 0.3 to 0.4 mg kg^-1.At the same time,biochar-based leaf surface conditioning bio-selenium-rich technology significantly improved the functional substance content of agricultural products（including chili soluble sugar and capsaicin content,garlic seed SOD activity,vitamin C,soluble sugar and soluble protein content,rice grain crude protein content and nitrogen phosphorus potassium nutrient content,tea amino acid content,etc.）,to improve crop nutrition quality.（2）Biochar-based soil conditioner significantly improves the root crown ratio and root vitality of crops,promotes crop growth and development,and has outstanding effect on the yield and quality of chili peppers and garlic seedlings.Compared with conventional,the application yield of Biochar-based soil conditioner increased by 40 to 60%,and plant height,leaf width,pseudostem length and pseudostem diameter of garlic seedlings were increased by 31.9%,11.8%,48.7%and 7.9%,respectively.The content of nitrate in garlic seedling was decreased by 44.7%,and the contents of capsaicin,vitamin C,soluble sugar and soluble protein in pepper were increased by 17.6%,67.0%,3.8%and 49.2%,respectively.（3）The combination of biochar-based leaf surface conditioning and biochar-based soil conditioning can not only greatly improve the yield,but also improve the quality of agricultural products,and the overall improvement range is more than 20%.The combination of biochar-based leaf surface conditioning and biochar-based soil conditioning enhances vitamin C content,soluble protein content,capsaicin content of more than 40%,reduces nitrate content by more than 45%,can fully meet the high-yield and high-quality requirements of healthy agricultural products,and the two conditioning techniques cooperate to maximize the benefits.In short,biochar-based soil conditioning and biochar-based leaf surface conditioning technology have a good effect on rice,chili and garlic seedlings to increase production and quality.Among them,the yield and quality effect of biochar-based soil health conditioning technology,especially the crude protein content of rice,the vitamin content of vegetables,and the control of nitrates,are better than leaf conditioners,but the yield and quality effect of agricultural products are optimal under the combination of the two conditioning techniques.Therefore,this technology can meet the scale of rice,tea,fruits and vegetables rich in selenium-rich healthy agricultural products production,hope to be further demonstrated and popularized in the future.