Reseach On The Effect Of The Plant Of Desert Grassland On Different Grazing Intensity

From the two aspects of vegetation and soil, it was studied on the effect of grazing intensity on the vegetation and soil of desert grassland on Sidunzi, Yanchi, Ningxia from June to October, that the effect of vegetation is the keystone. The results are showed as follows:(1) There were positive correlativity between grazing intensity and containing water of soil. While the grazing intensity was rose, the containing water of soil was rose too. The relation of the grazing intensity and the containing water of soil accorded with the cubic curve Y=5.7664-4.6122X+6. 7007X2-1.8552X3 (0 X 1.50) .(2 ) There was no distinct effect on the calendar of the pasturage by grazing intensity.(3) There was distinct effect on the living energy of the pasturage by the grazing intensity. When the grazing intensity was rose, the living energy of the pasturage was declined, especially for the excellent edibility pasturage.(4) It was a long-term result that the consistency of the pasturage was affected by the grazing intensity. So the variety of the pasturage is not distinct in one season. But, there was positive relation between the consistency of the pasturage and the grazing intensity in short-term. The more the containing water of the soil was, the more the consistency of the pasturage was.(5 )There was negative correlativity between the grazing intensity and the general coverage of the vegetation, the heavier of the grazing intensity was, the smaller of the general coverage of the vegetation was. The variational current of the coverage of the vegetation was rose firstly, and then declined. It was biggest of the coverage of the vegetation when the grazing intensity was 0.45 sheep/hm2.(6) There was negative correlativity between the grazing intensity and the standing crop of the pasturage, the heavier of the grazing intensity was, the smaller of the standing crop of the pasturage was. The variational current of the coverage of the vegetation was rose firstly, and then declined. It was the biggest of the standing crop of the pasturage when the grazing intensity was 0.45 sheep/hm2.(7) There was extremely negative correlativity between the grazing intensity and the biology yield of the root in 0~10cm soil, and the equation of the correlativity between the grazing intensity and the biology yield of the root in 0~10cm soil was the line, Y=3.3796-0.8247X (0 X 1.50) ; There was extremely negative correlativity between the grazing intensity and the general biology yield of the root in 0~30cm soil, and the equation of the correlativity between the grazing intensity and the general biology yield of the root in 0~30cm soil was the line, Y=1.5355-0.3865X (O X 1.50) . The heavier of the grazing intensity was, the smaller of the biology yield of the root was in 0-30cm soil.(8) The variational current of the standing crop of the Gramineae pasturage rose firstly, and then declined. It was the biggest of the standing crop of the Gramineae pasturage when the grazing intensity was 0.45 sheep/hm2.(9) There was distinct effect on the structure of the vegetation by different grazing intensity. When the grazing intensity became heavier, the yield and the proportion of the Gramineae pasturage declined. The curve of the Leguminosae pasturage seemed as "V", the curve of themixed pasturage seemed as "N", and the variety of the ratio of the yield between the Gramineae pasturage and the Leguminosae pasturage was accorded with the exponential equation.(10) The heavier of the grazing intensity was, the bigger of the avaliability was, and the bigger of the avaliability was only in one season.(11) Considered from the facet of ecology, the feasible grazing intensity was 0.45 sheep/hm2 and the feasible avaliability was 36.15%-13.29% in the desert grassland.