Application Of Pig Manure Biogas Slurry Based On Farmland Safety

Biogas slurry as a by-product of renewable energy,with the promotion of biogas engineering,its large output,storage and transportation problems have brought negative impact on the promotion of biogas power generation,seeking the way of waste resource utilization has been widely concerned for many years.Biogas slurry contains rich nutrients that can be used by plants,which is the basis for biogas slurry to be used as fertilizer in the field.The nearest return of biogas slurry to the field is also an option with the lowest economic cost in the way of biogas slurry resource reuse,and it is also an important link in the benign cycle of agricultural ecology.This experiment based on the structure features of livestock and poultry breeding field in Shenyang area,in view of the representative soil types in Shenyang,selection of corn for the selected crops,the pot experiment and indoor soil column leaching simulation test,the combination of farmland after biogas slurry application on crops and soil environmental impact,it is concluded that the optimal the biogas slurry level and farmland crops largest biogas slurry limit.The results show that:(1)After combined application of biogas slurry and biogas slurry fertilizer,soil p H,ammonium nitrogen,total nitrogen,total phosphorus,available potassium and available cation exchange capacity increased gradually with the increase of fertilizer application,while the contents of nitrate nitrogen and available phosphorus showed a trend of decrease.(2)The aboveground biomass dry weight of each fertilization treatment was higher than that of CK treatment without fertilization.The aboveground biomass dry weight of conventional nitrogen biogas slurry and biogas slurry fertilizer combined application was lower than that of CF treatment,while the aboveground biomass of excessive fertilization treatment was higher than that of CF treatment.(3)Indoor soil column leaching simulation test during the application of biogas slurry treatment irrigation,the concentration of nitrate in the leaching solution was the highest at the initial stage of biogas slurry treatment,the concentration first decreased and then increased,then continued to decrease and gradually stabilized;At the same time,the concentration of ammonia nitrogen was the highest in the initial stage of leaching,then suddenly decreased and remained at a low level,until the ninth time after leaching,the concentration of ammonia nitrogen rose again and gradually decreased to a stable level.The contents of nitrate nitrogen,ammonium nitrogen,total nitrogen,available potassium and available phosphorus in the soil surface gradually increased with the increase of biogas slurry application amount,and the contents of nutrients in the soil decreased with the deepening of soil layer.Soil p H,total phosphorus,total nitrogen,available potassium and CEC were significantly affected by biogas slurry fertilization in 0-20 cm soil layer,ammonium nitrogen and available phosphorus were mainly affected by biogas slurry fertilization in 0-40 cm soil layer,while nitrate nitrogen was affected by fertilization in 0-60 cm soil layer.(4)Comprehensive indoor and outdoor experiments showed that the optimal range of biogas slurry application was between 2N and 4N,that is,between 36.0kg N/ mu and72.0kg N/ mu,under conditions that did not affect corn quality and yield.The optimal range of60% fertilizer combined with biogas slurry is between 2N and 3N,that is,between 25.2kg N/mu and 43.2kg N/ mu.Considering the risk of leaching loss of biogas slurry,the optimal application range of biogas slurry is less than or equal to 1N amount,that is,18 kg N/ mu.