Study On The Impact Of The Typical Covering On The Ammonia And Greenhouse Gases Emissions From Cattle Manure

The accumulation of animal manure in animal feeding operations has caused a large amount of ammonia?NH₃?and greenhouse gas?CO₂,N₂O and CH₄?emission,and the resulted environmental pollution and greenhouse effect have currently become the global research hotspots.Quick and accurate evaluation of different management practices on NH₃ control is very important to identify a good practice for clean livestock production and lower the corresponding environmental risks.Screening the NH₃ reduction technology is conducive to the unified and efficient management of the manure in the livestock farming,as well as relevant control policies and technical standards for emission reduction.This study built up an automatic measurement system through combining the on-line measurement system?Innova1412i?and a serial of dynamic chambers using central unit.An experiment was carried out to explore how cover thickness affects NH₃ and greenhouse gas emission from stacked cattle manure.NH₃,CO₂,N₂O and CH₄ emission from stored cattle manure covered by straw?JG?,furfural residue?KZ?and vinegar residue?CZ?were measured?cover thicknesses of 0.5 cm,1.0 cm,and 2.0 cm?,using the established automatic measurement system.And the solid-liquid portion of rinsed vinegar grains was used to simulate rainfalls on the vinegar residues to study the effect on emission reduction.The main conclusions are as follows:?1?In the control treatment?CK?of JG,KZ and CZ experiments,the rates of NH₃emission from natural dumping cattle peaked on the first day,which were 207.88,112.77and 93.67 mg·m^-2·h^-1,respectively,and then quickly decreased within a week and tended to be flat.The NH₃ emission rate of cattle manure in the JG and CZ experimental groups was lower than 12 mg·m^-2·h^-11 at the beginning,and then gradually increased.After 6 and 14days,the NH₃ emission rate of each treatment tended to be consistent with the CK.The NH₃ emission rate of cattle manure treated in the KZ group began to be 65⁸7 mg·m^-2·h^-1,which rapidly reduced to 15 mg·m^-2·h^-11 on the second day together with the CK.?2?The NH₃ emission reduction rate of the JG experiment covered group reached37.36%,61.49%and 87.21%respectively in the first 6 days.The reduction rate for the entire experiment period?21 d?reduced to 25.78%,46.14%and 70.17%,respectively.The cumulative NH₃ emissions on the first day of each group in the KZ experiment accounted for 71.43%⁹1.42%of the entire experiment period?7 d?.The NH₃ emission reduction rate of the covered group reached 35.75%,31.76%and 54.56%,respectively.The NH₃emission reduction rate of the CZ experiment covered group in the first 14 days reached2.29%,35.22%and 84.97%,respectively,while the reduction rate of the whole experiment period?21 days?fell to-5.87%,15.58%and 60.25%.The addition of vinegar rinsing solution had no significant effect on NH₃ emission,and the NH₃ reduction of the group covered with rinsed vinegar residues still reached rate of 81.34%in the experiment.?3?Covering with different thicknesses of straw and furfural residue reduced the CO₂emission and increased the N₂O and CH₄ emission.For instance,the CO₂ emissions decreased by 12.44%³3.93%and 30.84%⁶0.37%,the N₂O emissions increased by119.66%¹77.88%and 26.61%¹05.05%,and the CH₄ emissions also increased by36.48%¹81.32%and 13.64%⁷9.38%,respectively.Covering vinegar residue reduced the CO₂ emissions from 9.12%to 20.55%and increased the CH₄ emissions from 100.00%to 163.82%.The trend of CO₂,N₂O and CH₄ emissions from cattle manure covering vinegar grains is the same as that of covering straw,furfural residue and vinegar residue,while the addition of vinegar rinsing solution had no significant effect on the emissions of CO₂,N₂O and CH₄.In terms of CO₂ equivalent?CO₂-eq?,the 2 cm furfural residue covered group increased the greenhouse gas emissions by 34.59%,and the 2 cm vinegar residue covered group reduced the greenhouse gas emissions by 16.87%,while the other groups had no significant impact on greenhouse gas emissions.?4?In the three experiments,the increases of TN and TP content and the decreases of TAN and TOC content were detected after the experiment.Correspondingly,except for the CK group of the CZ experiment,the C/N after the experiment was significantly lower than the initial value?P<0.05?.N/P of the treatments of the 1 cm and 2 cm groups in the JG experiment were also significantly increased?P<0.05?,but the N/P changes in the KZ and CZ experiments were not significant.The initial GI?Germination Index?of each experiment was less than 50%,and there were different degrees of increase after the experiment.In the JG and KZ experiments,the GI in the CK group was significantly higher than that in the 1 cm and 2 cm covering treatment?P<0.05?.However,the CK group and the covered group of the CZ experiment both increased significantly to more than100%.In summary,for the storage of cattle manure,covering is a simple and efficient NH₃reduction technology that can conserve nitrogen and improving the quality of cattle manure.Covering vinegar grains also has a reducing effect on greenhouse gases,and can also promote seed germination.