Decomposition Of Dung And Litter In Alpine Meadow-Tibetan Sheep System

Alpine meadow sheep is one of the important grazing livestock,sheep dung and litter are the grazing system key flowing carrier of material circulation and energy.Therefore,with Ma’qu county-Tibetan alpine meadow sheep blocks rotational grazing and continuous grazing system as the research object,studies the rotational grazing and continuous grazing two systems,four grazing rate(0 sheep/ha,4 sheep/ha,8 sheep/ha,16 sheep/ha,24 sheep/ha)and two grazing season(summer,winter)in the dung and litter decomposition.The main results were as follows: 1.The decomposition of dungSummer pasture,the quality of sheep dung within 18 months,organic carbon and N,P rate under 8 sheep/ha were significantly higher than other grazing rate(p<0.05),8 sheep/ha was significantly higher than no grazing plot(p<0.05),the quality of daily average rate was 0.913 mg/g,the rest grazing rate was not significant(p<0.05).Sheep dung within 18 months of NDF,ADF,fat,ash the decomposition rate of 8 sheep/ha was the fastest,C/N,lignin decomposition under 16 sheep/ha rate was the largest.Winter pasture,under 8 sheep/ha the quality of dung decomposition rate,organic carbon and N rate was significantly higher than other grazing rate(p<0.05),the rest grazing rate was not significant(p<0.05).Continuous grazing land,the quality of sheep dung under 4 sheep/ha,organic carbon and N,P decomposition rate were significantly higher than other grazing rate(p<0.05).The decomposition of dung change of fat,lignin,ash content was lower than the summer pasture,16 sheep/ha was lower than 8 sheep/ha in the return.Dung under 0 to 5cm soil,the microbial biomass and soil grazing activity was significantly higher than no grazing.In 0-5cm of soil,microorganisms in soil C,N and P are under 8 sheep/ha grazing rate was significantly higher than other grazing rate(p<0.05),no significant differences between other grazing rate(p>0.05);In 5-10 cm of soil,soil microbial C and P in 8 sheep/ha was significantly higher than other grazing rate(p<0.05).Summer pasture and winter pasture,dung decomposition 50% was 18 months and 21 months,down 90% was 59 months and 64 months,the fastest grazing rates were 9.3 sheep/ha and 9.6 sheep/ha.2.The decomposition of litterSummer pasture,the decomposition of litter under 8 sheep/ha within 18 months was significantly higher than other sheep grazing rate,8 sheep/ha,no grazing and 16 sheep/ha differences were not significant(p>0.05).The average quality daily rate was 0.960 mg/g,and 16 sheep/ha grazing rate difference was not significant(p>0.05).The quality of the litter,organic carbon and N,P,ash content,adipose decompose was the fastest under 8 sheep/ha,NDF,ADF,C/N ratio,lignin under 16 sheep/ha return was the largest.Winter pasture,litter decomposition under 8 sheep/ha rate was significantly higher than other grazing rate,and the differences between each of grazing rate significantly(p<0.05).Continuous grazing land,under 4 sheep/ha,organic carbon and N,P decomposition rate were significantly higher than other grazing rate(p<0.05).The quality of the litter decomposition rate,organic carbon and N,P,NDF,ADF,C/N ratio under 8 sheep/ha decompose fastest,fat,ash content,lignin under 16 sheep/ha return was the largest.Litter under 0 to 5cm soil,the microbial biomass and soil grazing activity was significantly higher than no grazing.In 0-5cm of soil,microorganisms in soil C,N and P are under 8 sheep/ha grazing rate was significantly higher than other grazing rate(p<0.05),no significant differences between other grazing rate(p>0.05);Soil microbial N under 16 sheep/ha grazing rate was significantly higher than other grazing rate(p<0.05).Summer pasture and winter pasture,litter decomposition 50% was 17 months and 25 months,down 90% was 56 months and 58 months,the fastest grazing rates were 8.9 sheep/ha and 8.4 sheep/ha.3.The main affect factors of dung and litterMain factors on litter decomposition rate of contribution to grazing(0.621)>soil moisture(0.536)>temperature(0.481)>initial C concentration(0.245)>initial N concentration(0.211)>initial P concentration(0.156);Main factors contribution for sheep dung decomposition grazing rate(0.649)>soil moisture(0.591)>temperature(0.501)>initial C concentration(0.251)>initial N concentration(0.231)>P concentration(0.167).The certain condition of climate,grazing rate,the higher the temperature,the greater the soil moisture was larger,the smaller the C concentration,N concentration,P concentration was smaller,the greater decomposition rate of the dung and litter.