L. Chinensis Grass Goats Grazing On The Grass Regeneration

The experiment was conducted to study the leaf regrowth dynamics of grasses, characteristics of vegetation, productivity of vegetation, NSC (nonstructural carbohydrate) and nitrogen of grasses under different grazing intensities on Leymus chinensis grassland. Not only can the relationship between grazing intensity and regrowth of vegetation be discovered, but also the appropriate grazing rate can be determined in the management of grazing system. It was shown that:(1) There were significant differences in the rate of leaf appearance, rate of leaf wither, leaf enlongation and rate of leaf senescence between different regrowth duration. The effect of grazing intensity is not significant. The maximum of the rate of leaf appearance, rate of leaf wither, leaf enlongation and rate of leaf senescence were found in plot PO, which showed that the leaf resource of L. chinensis was not utilized completely under the condition of no-grazing. The maximum of the rate of leaf appearance and leaf enlongation of Phragmites communis and Puccinellia tenuiflora were found in plot P2 and P3 respectively. The grazing intensity of the plot P2 and P3 belonged to middle level in the experiment. Therefore, the middle grazing intensity not only accelerated appearance of Ph. communis and P. tenuiflora, but also boosted utilizing efficiency. The research indicated that the rate of leaf appearance and rate of leaf wither of Ph. communis was higher than those of L. chinensis and P. tenuiflora, but its lifespan was shorter and the speed of leaf tissue turnover was higher. Thereby, the different time and type of utility of the foregoing three grasses must be determined respectively.(2) The height of grassland decreased with the increase of grazing intensity. The decrease degree of different grass was different under the same grazing intensity and month, and that of the same grass was differentin different month, which indicated that the edibility of different grass in the same month and that of the same grass in different month were different. There was an increasing tendency in the density of community with the increase of grazing intensity. The response of P. tenuiflora to grazing intensity was great and it adapted to grazing intensity by decreasing height and increasing density.Grazing was one of the factors that affected biomass. Proper grazing intensity could decrease the proportion of forbs in vegetation, which increased the proportion of grasses and improved the quality of grassland. Proper grazing intensity was benefit to the regrowth of herbage. The relationship was a quadric curve between the relative regrowth speed of the herbage and the grazing intensity. Thus, the moderate grazing intensity of 8-12 goats / m2 could be decided under the condition of the experiment. That was 3.3-5 goats / hm2 if the grazing seasons were 120 days and two hours per day. Not only could grassland be maintained to sustainable regrowth, but also farmers could gain animal production under the grazing intensity.(3) The NSC in different part of grasses decreased with the increase of grazing intensity. The NSC in the base stem of L. chinensis was sensitive to grazing intensity than that in leaf, but Ph. communis and P. tenuiflora were contrary. The NSC and nitrogen in grasses aboveground of PO ware not the highest, which showed that proper grazing intensity was benefit to the increase of NSC and nitrogen. NSC and nitrogen had correlation to the regrowth speed and the nutrition value, which showed that proper grazing intensity could accelerate the regrowth speed and improve the nutrition value of herbage.