Growth And PhysiologicaI Response Of Four Poaceae Grasses To Artificial Simulated Stress

Artificial simulated stress test was conducted on four grasses of Elytrigia intermedia, Bromus inermis, Leymus chinensis and Agropyron desertorum.It is the first time to propose a new concept of Pasture Stress Coefficient, which means in grazing, a product that multiplying by total trampling times and total animal weight, in certain unit of time and grassland area.The result showed that,(1)The best period of trampling was9-11days, in the conditions of having enough soil water, cutting remaining15cm, stocking rate1.2. It got a value of trampling stress3.76*109/m2and of stress coefficien10.0in the treatment.(2)Regeneration were all intensively in9-11th day within the trampling period of4grasses. A next highest grass production was expressed in the period. Dissolubility protein, carbohydrate, nitrogen and chlorophyll were expressed highest content. Absorbing to phosphorus was higher on both heavy and light trampling stress, whereas there was a lower absorbing in the middle trampling and no stress.(3)Tillering was promoted and cluster diameter expanded in the treatment by cutting off flag leaf, if tip point of plant was not hurt.(4)Grass was always hurt by any stress treatments, however, a suitable rate of stress might allow grass having a dynamic balance between hurt and recovering. It is must benefit for pasture sustainable long term use.(5) The best to worst order in the stress of4grasses was Agropyron desertorum(Fisch.)Schult, Leymus chinensis, Bromus inermis and Elytrigia intermedia.