施肥对荒漠草原退化草地植被特征的影响

Effect of fertilizations on vegetation of the degraded desert steppe

草地退化是一直为人们关注的问题,施肥是草地恢复的有效手段之一。为了解荒漠草原退化草地上氮、磷等肥料施用后对退化草地植被特征的影响,本研究利用尿素、过磷酸钙和有机磷酸二铵等,在内蒙古赛汗塔拉荒漠草原退化草地上进行了施肥试验。结果表明,尿素对植被盖度、密度的影响都没有达到显著水平(P>0.05),而在3.8kg100m-2的施肥水平下,地上生物量比对照显著的增加38.8%(P<0.05)。过磷酸钙对植被盖度、密度和生物量的影响均没有显著的影响(P>0.05)。有机磷酸二铵在施肥量是1.25kg100m-2时,盖度和密度分别比对照显著增加24%和31.8%;在1.25和5.15kg100m-2的施肥水平下,地上生物量比对照显著的增加53.1%、56.1%(P<0.05)。基于同样的纯氮添加量的比较说明,有机磷酸二铵与尿素相比,在地上生物量和密度方面影响更显著。

Degradation of grassland is always what people are concerned about, and fertilization is a effective way to vegetation restoration. To test the effect of fertilizers of N and P on the degraded desert steppe, the Urea, Calcium Superphosphate and Diammonium Phosphate were fertilized on the degraded desert steppe in Saihantala in Inner Mongolia. The results showed, no significant influences of urea on plant cover and density were observed. At 3.8 kg 100m-2 of urea, the aboveground biomass was significantly higher by 38% than CK （P〈0.05）. The Calcium Superphosphate used in this study had no effeetives on the plant cover, density and aboveground biomass. The plant cover and density were significantly higher than CK by 24% and 31.8% receptively when the fertilization of Diammonium Phosphate was at 1.25 kg 100m-2 （P〈0.05）. At 1.25 and 5.15 kg 100m 2 of Diammonium Phosphate, the aboveground biomasses were significant higher than CK by 53.1%, 56.1% receptively（P〈0.05） The comparison based on N showed that the Diammonium Phosphate was effective more than the urea in the as peet of the aboveground biomass and plant density on the degraded desert steppe.