Response Of Pasture Yield And Quality For Different Mowing Period And Different Istubble Height And Different Years

The characteristics and nutrients of plant and soil were analyzed in stationary plots, S. baicalensis、C. pediformis and L. chinensis、forbs steppe of Hulunbeier, Inner Mongolia from2009to2011. The main results were shown as follows:1The plants of Gramineae and Compostion are the mian composition.Defoliation of successive3years, the proportion of gramineae gradually increased with the mowing years increased and mowing period delay, and the proportion of plants that Leguminosae, Rosaceae, Cyperaceae were decreased with mowing years increased. Stipa baicalensis cluster fragmentation and miniaturization by mowing for many years which also made L. chinensis, Cleistogenes squarrosa and Koeleria cristata dwarf.2The index of community Margalef, Shannon-wiener, Simpson, and Pielou were gradually decreased with the frequency of mowing increased, the number of species of community were reduced and complexity of the community were declined by mowing.3The community biomass has obvious seasonal characteristic, and the change was "the single-peak type". The aboveground biomass of meadow was gradually reduced as for the stubble, and aboveground biomass of stubble7cm down the fastest, followed by3cm, the slowest was5cm.4Mowing can promote the content of crude protein and crude fat, then the changes that content of crued protein had obvious seasonal characteristics, and the peak in August15th and then fell rapidly. Crude protein content witch stubble7cm is the hightest in2010and2011. In addition to the first time mowing in2009outside, but decreasse of crude protein content witch5cm is the lowest.5The soil was less influenced short-term year after year mowing, but soil organic matter, total N and available N content decreased with long period of successive years mowing.