Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA.
Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA.
Sci Total Environ. 2015 May 1;514:290-7. doi: 10.1016/j.scitotenv.2015.01.066. Epub 2015 Feb 7.
With the increased use of fungicides in cultivated regions such as the southern High Plains (SHP), U.S., unintentional runoff and drift as well as direct overspray during aerial application lead to environmental exposures that may influence soil microbial communities and related biogeochemical functioning. Our goal was to examine the effects of two popular fungicides Headline (pyraclostrobin) and Quilt (azoxystrobin/propiconazole) on respiration from soil microbial communities in playa wetlands embedded in cropland and native grassland and their adjacent watersheds. We monitored fungicide effects (at levels of 0, .1×, 1× and 10× the label rate) by measuring respiration from plant matter amended soils collected from 6 cropland and 6 grassland playas and uplands. In addition, differences in microbial community structure among land use types were determined by measuring ergosterol levels in cropland and native grassland playas and uplands. Native grassland playas and their associated watersheds had up to 43% higher soil respiration rates than cropland playas and watersheds, indicating higher soil microbial activity. Application of either fungicide had no effect on soil respiration at any concentration in either land use type or habitat type (playa/watershed). Native grassland playas and watersheds had 3 and 1.6 times higher ergosterol content than cropland playas and watersheds. The lack of soil respiration response to fungicide application does not necessarily suggest that fungicides used in this study do not affect non-target soil microbial communities due to potential compensation by other biota. Future studies should further elucidate existing microorganism communities in playas and their watersheds.
随着杀菌剂在美国南部高平原（SHP）等种植区的使用增加，无意的径流和漂移以及航空应用中的直接喷雾导致了环境暴露，这可能影响土壤微生物群落和相关的生物地球化学功能。我们的目标是研究两种流行的杀菌剂 Headline（pyraclostrobin）和 Quilt（azoxystrobin/propiconazole）对种植在农田和原生草原中的湿地以及其相邻流域中土壤微生物群落呼吸的影响。我们通过测量从农田和原生草原湿地和旱地采集的添加植物物质的土壤的呼吸来监测杀菌剂的影响（在 0、0.1×、1×和 10×标签率的水平下）。此外，通过测量农田和原生草原湿地和旱地中的麦角固醇水平来确定不同土地利用类型之间微生物群落结构的差异。与农田湿地和流域相比，原生草原湿地及其相关流域的土壤呼吸率高达 43%，表明土壤微生物活性更高。在任何浓度下，应用这两种杀菌剂都不会对任何土地利用类型或生境类型（湿地/流域）的土壤呼吸产生影响。与农田湿地和流域相比，原生草原湿地和流域的麦角固醇含量分别高出 3 倍和 1.6 倍。土壤呼吸对杀菌剂应用没有反应并不一定表明本研究中使用的杀菌剂不会影响非靶标土壤微生物群落，因为其他生物群可能会产生潜在的补偿作用。未来的研究应该进一步阐明湿地及其流域中现存的微生物群落。
