Decomposition Of Litter And Dung In Typical Steppe-Tan Sheep Rotational Grazing System And Its Ecosystem Service

In the grazing system, litter and dung associated with livestock, vegetation and soil, the decomposition process is the key link of ecosystem material circulation, for the maintenance of ecosystem service function has important significance. The experiment in the typical steppe in the Loess Plateau-Tan sheep grazing system as the research object, the set of grazing,2.67 sheep/ha,5.33 sheep/ha,8.67/ha four sheep grazing rates.warm and cold season two grazing seasons, analysis of litter and sheep manure decomposition for stocking rates and grazing season response, and ecological system the value of service, and strive for reasonable prairie reasonable utilization of reference. The main results are as follows1.Litter DecompositionThe litter decomposition rate in warm pastureof in turn:5.33sheep/ha>2.67sheep/ha >8.67sheep/ha> no grazing. The seasons of the year decomposition rate, summer> spring> autumn> winter. Unit area prairie litter a year decomposition amount were:5.33sheep (14.30 g/m2)> no grazing (11.28 g/m2)≈2.67sheep (11.23 g/m2)>8.67/ha (7.35 g/m2).Litter decomposition rate and grazing rate in a certain range inner correlation.The litter decomposition rates in cold pastureo were as follows:5.33sheep/ha>2.67sheep/ha > no grazing>8.67sheep/ha. The seasons of the year decomposition rate:spring summer>winter> autumn>> winter,in one years, grassland area of litter decomposition amount as follows:no grazing (11.28 g/m2)>5.33sheep/ha (9.94g/m2)>2.67sheep/ha (8.47g/m2)>8.67sheep/ha (6.94g/m2); less than the same grazing in warm pasture. Soil temperature on litter decomposition roles than soil humidity. Litter decomposition and lignin to the general relation: Y=0.3384x2-16.262x+202.43;the relationship with cellulose:y=0.0836x2-7.0716x+157.45.2. carbon, nitrogen, phosphorus decomposition of litterThe carbon decomposition rate of litter in warm pasture:5.33sheep/ha>8.67sheep/ha >2.67sheep/ha> no grazing, the whole year decomposition rates were 29.92%,26%,22.63% and 20.41%. The carbon decomposition rate of litter in warm pasture:were 2.67sheep/ha (20.25%) <5.33sheep/ha (22.09%)<8.67sheep/ha (25.09%), with grazing enhances and rise, but were less than that of the same grazing rates in warm pasture.The rate of decomposition of the season between The fastest decomposed is spring, thr slowest is winter.The N decomposition rate of litter in warm pasture:8.67 sheep/ha>5.33 sheep/ha >2.67sheep/ha>ck, decomposition, a year later, under different stocking rates in organic carbon decomposition rate was 38.64%(CK)、46.71%(2.67)、44.13%(5.33 sheep/ha),50.22%(8.67 sheep/ha)/ha in one year.cold season), The N decomposition rate of litter in cold pasture are 36.14%(2.67sheep/ha)、50.04%(5.33sheep/ha)、55.59%(8.67sheep/ha). Summer decomposed is the fastest, winter is the slowestThe P decomposition rate of litter in warm pasture:5.33sheep/ha>8.67sheep/ha>2.67sheep /ha> no grazing,the decomposition rates of a year were 60.61%、56.87%、50.05% and 38.31%. A year later, The P decomposition rate of litter in cold pasture were 36.64%(2.67sheep/ha)、47.79% (5.33sheep/ha)、33.52%(8.67sheep/ha).The decomposition rate of C、P are more quickly than organic carbon. Ecological stoichiometry of C/N along with the time increasing. 3..Dung decompositionBoth warm and cold pasture sheep manure decomposition rate in turn were 8.67sheep/ha >5.33 sheep/ha>2.67 sheep/ha, the different grazing decomposition rate of sheep dung in a year rates were 51.25%、40.06%、36.8% and 49.29%、46.7%,40.03%, decomposition rate is linear positive correlation with grazing rate. cold pasture decomposition rate less than warm season. Warm pasture in winter, spring two season decompose more quickly, cold pasture,summer grazing decomposed is the fastest. And lignin in general:y=0.5184x2-30.849x+466.06, and cellulose relations:y=0.0275x2+1.5565x-8.7064. 4.Ecological service valueThe ecological service value of litter decomposition, both warm cold season pasture were followed by:5.33sheep/ha>2.67 sheep/ha>8.67/ha sheep, respectively 53.91yuan·ha-1·a-1、 40.54yuan·ha-1·a-1、30.65yuan·ha·1·-a-1and 45.36yuan·ha·1·a-1、40.53yuan·ha-1·a-1, 35.19yuan-ha-1·a-1. no grazing ground litter decomposition for 45.93,ha-1·a-1.Sheep dung decomposition of the ecological service value with grazing rate increases, grazing in warm and cold pasture grazing land respectively 49.94yuan·ha-1·a-1、100.14yuan·ha-1·a-1、159.49yuan·ha-1·a-1�'�30.59yuan·ha-1·a-1、56.46yuan·ha-1·a-1、11704yuan·ha-1·a-1.The litter decomposition, grazing rate of 5.33sheep/ha decomposition rate the fastest, in sheep dung decomposition, grazing rate of 8.67sheep/ha decomposition rate of the fastest.