Research On Degradation Of Organic Components And Variation Of Nitrogen Forms In Pig Bio-bed Litters

With the rapid development of society, the contradiction between the traditional medicinal powder raise pattern and cultivated land resources has become increasingly prominent, and the environmental pollution is becoming more and more serious. All life activities of livestock and poultry are in the litters in bio-bed raising mode, and the key of the emerging mode is management and maintenance of litters. Therefore, to explore the degradation of organic matters in litters and influence factors, and the transformation rules of different nutrient forms and the effect to the lower soil layer under the litters becomes very interesting meaningful. Moreover, it’ll also be accepted to help us select appropriate litter ratio in practical breeding process, and make accurate evaluation about the use time of pig farms according to the environmental effects. This research chose Nanjing Liuhe fermentation bed farm and Siyang Tianpeng farm as the research object, and studied degradation characteristics of lignin, cellulose, hemicelluloses etc in different litters; we explored the influencing factors in degradation process by measuring water content, pH, C/N ratio and enzyme activities in litters; analyzed the changes of different nitrogen in litters and the soil layer under litters to study the transformation characteristics of different nitrogen forms, and it can provide theoretical support for scientific application of fermentation bed and reducing the burden on the environment. According to the experimental data, the main conclusions are as follows:(1)The decline of cellulose, hemicelluloses and lignin in litters that was token rice husk and wood sawdust for raw materials was lower than the litters which mixed with lees and fungus chaff during the breeding process; C/N ratio was affected by the material composition in litters, the C/N ratio reduced to values that the microbial activities were most vigorous (C/N=25) was faster in the litters mixed with lees and fungus chaff.(2)The percentages of cellulose in organic materials were decreased in all the three different litters, while the percentages of lignin were increased; the proportion of hemicelluloses in organic material was slightly raised in the litter that was token rice husk and wood sawdust for raw materials only, while the content of hemicelluloses was falling in the litters which mixed with lees and fungus chaff.(3)In the 0-40cm litter layer, the enzyme activities were decreasing with the depth increasing; in the 40-80cm soil layer under the litter layer, the enzyme activities were slightly increased with the litters’using time longer.(4)In the fermentation bed litters, catalase and cellulose activities significantly increased but protease activity tended to decrease with time prolonger.(5)With the litters kept in use longer, the water content in litters displayed a trend of continuous decrease, so we should be timely supplement moisture in order to ensure the pig manure’s normal degradation; the pH value changed between 6.0 and 8.5, and this case can meet the needs of microbial fermentation.(6)The content of TN, alkali-hydrolyzed nitrogen and NO3-N in the litters showed increasing trend constantly, while NH4+-N displayed the decreased trend as time prolonger.(7)The organic matter content in litters was decreased continuously, while it followed a rising trend in the soil layer under the litters.