有机肥与补播对退化人工草地植被与土壤的影响

Effect of Organic Fertilizer and Reseeding on Vegetation and Soil in Degraded Artificial Grassland

在青海省共和县,2020~2021年连续两年评估施有机肥、补播川草2号老芒麦+北林202紫花苜蓿(接种根瘤菌)、补播川草2号老芒麦+北林202紫花苜蓿对退化人工草地植被群落结构、土壤温度、湿度和电导率的影响。结果表明:施有机肥和补播均能提高退化人工草地植被盖度、高度和地上生物量,且施有机肥对植被盖度的促进作用显著(P<0.05)。施有机肥和补播共同作用能显著增加植被盖度,但植被高度和地上生物量与单施有机肥和单补播处理相比无显著差异。北林202紫花苜蓿接种根瘤菌后补播,对植被的恢复效应增强。在恢复处理当年,有机肥结合根瘤菌处理的植被Pielou指数显著高于不施有机肥的CK(P<0.05),第2年单补播不接菌的植被Shannon-Wiener指数和Pielou指数显著高于其他处理(P<0.05)。施有机肥或补播也影响土壤的温度、湿度和电导率,其中12 cm深度的土壤湿度和电导率在施有机肥的当年显著增加(P<0.05)。

In this study,we evaluated the effects of organic fertilizer,reseeding Elymus sibiricus‘Chuancao No.2’+Medicago sativa‘Beilin 202’and reseeding Elymus sibiricus‘Chuancao No.2’+Medicago sativa‘Beilin 202’inoculated with Rhizobium on the vegetation community structure,soil temperature,soil moisture and electrical conductivity of degraded artificial grassland in Gonghe county,Qinghai province for two consecutive years from 2020 to 2021.The results showed that both the organic fertilizer and reseeding could increase the vegetation coverage,height and aboveground biomass of degraded artificial grassland,and the application of organic fertilizer had a significant effect on the vegetation coverage(P<0.05).The interaction effect of organic fertilizer and reseeding on increasing vegetation coverage was significant(P<0.05),however,there was no significant difference between the interaction and the treatment of applying organic fertilizer alone or reseeding alone in terms of vegetation height and aboveground biomass.Medicago sativa‘Beilin 202’was inoculated with Rhizobium and then reseed,which enhanced the effect of vegetation restoration.In the year of restoration,the Pielou index of vegetation treated with organic fertilizer and Rhizobium was significantly higher than that of CK without organic fertilizer(P<0.05),and the Shannon-Wiener index and Pielou index of reseeding vegetation in the second year were significantly higher than those of other treatments(P<0.05).The application of organic fertilizer or supplementary seeding also affected soil temperature,moisture and electrical conductivity,and the soil moisture and electrical conductivity at 12 cm depth increased significantly in the year of organic fertilizer application(P<0.05).