亚洲一区欧美在线,日韩欧美视频免费观看,色戒的三场床戏分别是在几段,欧美日韩国产在线人成

Aimed to the serious problem of soil compaction and grassland degradation on account of long-term grazing overload, a 9ST—460 vibration spacing scarifier for meadow was designed. The loosing soil parts of interval ladder framework were adopted. By the exciting force produced by the vibration system which is composed of connecting rod and crankshaft to loose soil, the high-solid soil was achieved to loose on the condition without damage to grassland vegetation. Experimental results showed that the scarifier has the ideal loosen effect in the forward speed of 1m/s and vibration frequency 10.0Hz. The test showed that the rate of vegetation destruction is 1.6%, tillage depth is 20.01cm, scarification ratio reaches 43.4％, and productivity reaches 0.85hm2/h. The average soil bulk density and the average firmness reduce by 30.0% and 48.8%, respectively after loosing soil. The yield of natural grassland and artificial grassland increases by 73.99% and 68.65%, respectively. The tilled soil forms the spacing cultivated horizon adapting to the growth of grass. The effect is obvious to improve the grassland ecological environment and improve grass production. 