不同强度短期放牧对高寒草甸土壤理化性质的影响OA

In order to explore the effects of short-term grazing with different intensities on the physicochemical properties of alpine meadow soil,a 5-year grazing-prohibited alpine meadow grassland was selected as an experimental plot in Jiacang village,Luqu county,Gansu province.Healthy and disease-free adult yaks with similar weight(300 kg,calculated at 5 sheep units per yak)were selected as experimental animals.Four grazing modes were used such as prohibition grazing(G0),light grazing(13 sheep units/hm2,G1),moderate grazing(17.5 sheep units/hm2,G2),and heavy grazing(32.5 sheep units/hm2,G3)for 120 days.The results showed that grazing significantly reduced the content of organic carbon(SOC)and total nitrogen(TN)in grassland soil(P<0.05),increased soil pH value and nitrate nitrogen(NO3--N)content(P<0.05);with the increase of grazing intensity,the total phosphorus(TP),ammonia nitrogen(NH4+-N),available phosphorus(AP),and available potassium(AK)in grassland soil showed a trend of first increasing and then decreasing,TP,AP,and AK contents all reached their maximum values under G1 grazing conditions and were significantly higher than other grazing intensities(P<0.05).In summary,it can be concluded that in practical production,adopting G1 grazing intensity in the short term is more suitable for sustainable utilization of grasslands and is beneficial for the development of grassland soil.