Study On The Beginning And Finishing Grazing-Period Of The Spring And Autumn Pasture In Army Horse Farm Of Zhaosu

Grazing is the most essential and significant means in the utilization of grassland, and it is also the important reason that causes the degradation in grassland. Establishing a "Man-grass-animal" harmonious relationship guided by utilizing the growth rules of forage is very important. Rational grazing-intensity and grazing-period are the keys to utilizing grassland. In the research, the Army Horse Farm of Zhaosu is selected to discuss the effect on spring and autumn grassland under different grazing-height, in the hope of achieving the benign circulation of grassland ecosystem and improving the level of animal husbandry. This research takes the forage-height as the index to find the beginning grazing period. It would be convenient and scientific for the staff to flexibly use. This research adopts the sample-line method and simulating-grazing method to study five types grassland. The research results are as followed: (i) The beginning periods of the supreme daily biomass of each grassland types are consistent, from June 3rd to June 18th. (ii) The daily biomass of each grassland types are different significantly, and the highest is 42.84g/㎡ in the winter pasture of even place in the valley. Act as 3.13times, 6.54times, 2.92times and 2.09times to type 1st, 2nd, 3rd and 5th separately. (iii) The relatively daily biomass of each grassland type is related to the community structure, and the simpler the community structure is, the shorter the continued period of the supreme daily biomass is. (iv) With grazing-height increased and the utilization period deferred, the regrowth-height of needle grass increases accordingly, and reaches the highest height to 17cm. (v) According to the above research, in the spring and autumn pasture (the most is needle grass) in Zhaosu basin, the rational beginning grazing period in spring is when the main forages grow to about 17cm. The rotational grazing interval is 20 days. Animal would enter the summer pasture on July 5th. The rational utilization period of spring and autumn pasture in autumn is from September 15th to October 5th.