Abstract
A trial treated by two levels of grazing frequency and N fertilization was conducted to compare and evaluate the effects of snow cover on sward vegetation and soil N on grazinglands. Significant differences in pre-snow grass mass between two treatment levels still maintained after snow melting. Positive responses of total mass and standing crop to different N fertilization levels found at pre-snow cover were not detected at post-snow cover. Grass to litter ratios reduced from pre- to post-snow cover, especially at low grazing frequency. Tiller density of grasses in same treatments did not differ significantly between pre- and post-snow cover, while N fertilization had positive effects on tillering either before snow cover or after snow melting. High N and frequent grazing caused increases in total nitrogen (TN) contents as 16.6 and 8.2% respectively during pre-snow cover. TN contents post-snow cover increased compared to pre-snow cover. There were significant increases in available nitrogen (AN) contents pre- and post-snow cover at high N fertilization, but no significant differences between grazing frequencies. AN contents after snow melting considerably rose as average 3.2-fold for that pre-snow cover.
