The Effects Of Different Degradation Gradient To Spatiotemporal Heterogeneity Of Forage Nutrition In Meadow And Typical Steppe Grassland

The aim of this paper was to discuss the change of herbage dry matter and main nutrition content in meadow and steppe in July and August ,2006. The results were as follows:The study on the change of herbage dry matter and nutrition with the change of grassland degradation in different grazing intensity .It shows heterogeneity of time and space ,the result as follows:1 The yield of herbage dry matter and Crude fiber content reduced with the increase of grazing intensity .But the content of Crude Protein, ash and nitrogen-free extract were oppositionary.2 From the change of herbage nutrition with flying of time, The content of ash and nitrogen-free extract were no different in July and August .But Crude Protein content was obvious lower in August than that in July .As time went on ,content of Crude fiber dropped in CK and light plot, and increased in moderate and heavy plots. The change of content on herbage dry matter was oppositionary to Crude fiber .3 The model between herbage dry matter and nutrition :The regression analyze of the component factor of herbage dry matter in meadow July and August was following: y=2.17529x1-22.49615x3-19.80347x4+3.80387x5(R2 = 0.9218,p<0.01) The regression analyze of the component factor of herbage dry matter in Steppe July and August was following: y= 4.37349x1-7.44589x2 (R2=0.9044 ,p<0.01)4 In different time and space ,Crude Protein, ash and Crude fiber had significantly relation with dry matter yield. But the content of ash was significantly negatively relation with crude protein. We should select these five indexes as important indexes to evaluate grassland quality,which could avoid the phenomenon on domestic animal nutrition unbalance when grazing .