加入不同比例黄土对粪肥碳、氮养分保蓄的影响

采用室内培养方法研究了加入不同比例黄土对猪粪、牛粪两种粪肥培养过程中碳、氮养分保蓄及养分含量的影响。结果表明:加入黄土后猪粪CO_2和NH_3释放量显著降低,碳、氮保蓄率高于未加黄土处理;加入黄土后牛粪NH_3释放量显著降低,氮素保蓄率提高,而碳素保蓄率无明显变化,这与牛粪碳氮比相对较高,水溶性物质含量低,且较难分解的纤维素和半纤维素含量高,相对难以分解有关。随着黄土加入量的增加,土粪中各养分含量逐渐降低,这与加入黄土对粪肥养分的稀释作用有关。可见,加入适量黄土对减少粪肥分解过程中温室气体排放,保蓄粪肥碳、氮养分有重要作用。

Effects of loess additions on carbon and nitrogen retention in manures

With rapid development of animal production in China, more and more manures have been generated. Nutrient losses from the manures result in severe environmental problems. Therefore, how to conserve nutrients in the manures deserves further study. An incubation experiment was carried out to examine the influence of adding different rates of loess on CO₂ and NH₃ emissions from two manures(pig manure & cow manure) and retention capacities of carbon and nitrogen in the manures. Results showed that the addition of loess significantly reduced the emissions of CO₂ and NH₃ gases from pig manure,and increased C and N retention in the pig manure. For cow manure, adding loess reduced the NH₃ emissions during the incubation, whereas it did not affect CO₂ emissions. Such different effects of loess on CO₂ emissions between two manures were due to the differences in manure properties. Compared with pig manure, cow manure was higher in cellulose and semi-cellulose and in C/N ratios, but lower in soluble substances, thus having very slow decomposition rates. However, increased addition of loess might reduce the content of nutrients in the mixture because of dilution effect. It is concluded that adding loess to manures has positive roles in reducing greenhouse gas emissions, and nutrient losses.