Effect Of Different Conditioners On The Aerobic Composting Process Of Chicken Manure And The Effect Of Returning Organic Manure

In recent years,with the development of the livestock and poultry breeding industry,emissions of livestock and poultry have gradually increased,posing a serious threat to the local atmosphere,water sources,soil and other environments,and also causing a large amount of nutrient loss.Aerobic composting,as a relatively simple waste treatment method,is suitable for the recycling of livestock and poultry manure.The high moisture content of livestock and poultry manure and the inappropriate carbon-nitrogen ratio are difficult to provide a suitable environment for the microorganisms in it.A large amount of greenhouse gases generated during the composting process will damage the ecological environment and cause a large amount of nitrogen and nutrient losses.The mechanism of action on plant growth and soil nutrients.This study was conducted through the indoor compost test,indoor pot test,and indoor related index analysis from the following four aspects:（1）This chapter Based on the 2017 aquaculture data measured in Hainan,the excretion coefficient method and crop grain ratio were used to calculate the total amounts of nitrogen,phosphorus and potassium nutrients in livestock manure and straw.We analyzed the environmental carrying capacity,environmental pollution of livestock and poultry and the potential of organic fertilizers to replace chemical fertilizers with different returning proportions in Hainan.（2）Different aerobic composting with different water content,aeration rate,and biochar with chicken manure and wood chips to explore greenhouse gases Discharge conditions;（3）Use wood chips,coconut bran,pineapple leaves,cassava stalks and bagasse mixed with chicken manure respectively to conduct aerobic composting tests to investigate the maturation and nutrient conversion;（4）use test 2 to mix different compost products with soil Pot experiment to explore the effects of different leavening compost products on the growth of Chinese cabbage and soil nutrients;（5）Plant another season of Chinese cabbage on the basis of Experiment 3,and explore the improvement effect of soil physicochemical properties without compost products.The main conclusions of the study are as follows:（1）Results showed that in 2017 the total amount of livestock and poultry excrement in Hainan was 11.109 million tons.When the livestock manure was returned to the agricultural fields,the aquaculture carrying capacity in the province was 675.15million pig equivalents.The pollution risks of agricultural lands in Ding’an County and Haikou Areas were relatively high,0.98 and 0.81 respectively.The total nitrogen,phosphorus and potassium nutrients of straw and livestock manure in Hainan were145,000 tons,and the proportions of returning to fields were 1/3,2/3 and 100%,the replacement potentials of organic fertilizers was 4.2%,7.1%,and 14.1%,respectively.（2）This experiment uses different composting rates,moisture content,and biochar gradients for mixed composting.All treatment temperatures are maintained at55℃for more than 7 days,and the p H is greater than 9,exceeding the organic fertilizer limit.EC and seeds after all treatments are completed The germination index（GI）reached the standard after the completion of composting,indicating that the compost was ripened;as the ventilation rate increased,the CO₂ emissions increased;at the same time,as the proportion of biochar added increased,the CO₂ emissions gradually decreased;because the ventilation rate affected the reactor The concentration of oxygen in the body,this experiment found that as the ventilation rate increases,CH₄decreases,and at the same time,it is positively correlated with the biochar addition ratio.No significant effect of moisture content on CO₂and CH₄ emissions was found in this experiment.The ventilation rate is 0.4 N·kg/h,and the NH₃ emission is the lowest,only 86.28g,but there is no significant correlation.Due to the high p H of each treatment,the NH₃ emission in this experiment is higher than other experimental results,while the N₂O emission is low.In future tests,it is necessary to add an appropriate amount of acidic substances to lower the test p H,such as acetic acid,sulfuric acid,and the like.Through orthogonal analysis,we can know that the optimal ratio of different moisture content,ventilation rate and biochar:65%moisture content,ventilation rate 0.4 N·kg/h,and biochar 12%.（3）Adding a leavening agent during the composting process can effectively improve the ventilation status of the compost and enhance the composting effect.Under the same initial conditions,all treatments can reach maturity.The duration of the high-temperature period of all treatments is longer than 5 days.After the composting process,the p H is stable between 7.5 and 8.5,and the EC values are lower than 4000μs/cm.There is no harm to the crops and the seed germination index（GI）is greater than 80%after each treatment of composting.From the perspective of nutrient conversion,the degree of degradation of organic matter in sawdust treatment was higher,reaching 56.18%,and the lowest was cassava stem,which was 37.59%.After composting,the highest nutrient content TN was bagasse treatment,2.28%,followed by sawdust,2.26%;the highest TP was pineapple leaf treatment,3.59%,followed by sawdust treatment,3.06%.Synthesizing the whole composting process,sawdust as a leavening agent is the best choice for chicken manure aerobic composting.（4）This experiment found that compost products can increase the chlorophyll content of pakchoi,but the effect was not significant through the return of different leavening compost products to the field.At the same time,cassava stalk treatment did not fertilize and fertilization treatment could significantly increase the biomass of pakchoi.No fertilizer treatment reduced pakchoi biomass.Chemical fertilizer,sawdust,cassava stalk,and bagasse treatment can significantly increase the total nitrogen content of pakchoi without fertilization,an increase of 16.85%to 57.83%;each fertilization treatment can significantly increase the phosphorus content of pakchoi without fertilization,pineapple leaf and bagasse treatment Chemical fertilizer treatment can significantly increase the phosphorus content of pakchoi.There is no significant difference in total phosphorus nutrient accumulation when different leavening compost products are returned to the field.Compared with chemical fertilizer application,the compost products could significantly increase soil organic matter and total nitrogen content,with growth rates of 16.44%-57.06%and 68.75%-102.08%,respectively.The treatment of coconut bran and pineapple leaves significantly increased soil total phosphorus compared with chemical fertilizer application.Content,the increase rates were 61.90%and 47.62%,respectively,and there was not much difference between different compost products;the return of different compost products to the field without fertilization and chemical fertilizer treatment can significantly increase soil p H.（5）Through two seasons of pakchoi planting,the compost products can increase soil nutrient content compared with no fertilization and chemical fertilizer treatment;returning compost products to the field can significantly reduce soil bulk density,which decreases by 21.57%～43.14%;wood chips and pineapple Compared with chemical fertilizer treatment,leaves,cassava stalks and bagasse treatment can significantly increase the total soil porosity,with an increase range of 20.77%to36.05%;pineapple leaf and bagasse treatment can increase soil capillary porosity compared with chemical fertilizer treatment,with an increase of 4.52%and 12.68,respectively.%.After the soil aggregates were treated by wet and dry sieving,the average weight and diameter of sawdust were the highest,reaching 2.20,followed by no fertilizer treatment and chemical fertilizer treatment,and coconut bran treatment was the lowest,only 1.39.The results of this study have smaller average weight diameters,indicating that the soil structure stability in Hainan Province is poor.