Submission Type
Oral Presentation
Abstract
Restoring agricultural lands back to grassland aims to reverse many negative impacts of agriculture on the ecosystem including nutrient export from soil and depletion of soil carbon. Planting prairie on agricultural soil promotes recovery of soil microbial biomass and their enzymes, which create demand for nitrogen by microbes to reduce the rate of nutrient cycling and loss. A complicating factor in the development of a restored grassland the influence of several anthropogenic global changes including increasing frequency of drought and nutrient enrichment. Drought has been found to negatively affect microbial biomass, soil enzyme activity and nutrient cycling. Nutrient (often N) enrichment has been found to negatively affect C in the microbial biomass and soil enzyme activity while increasing N microbial biomass and soil enzyme activity. This research sought to investigate how drought and nutrient availability affected soil microbial biomass and soil enzyme activity in a long-term restored grassland. Only nutrient availability was found to affect either measurement, not drought or its interaction. Reduced N soils had the greatest microbial carbon biomass and enzyme activities compared to control and enriched N soils. Drought had no effects in the third year of imposed drought potentially due to timing of sampling in the field as the restoration plots had experienced severe rainfall within days of sampling. This resulted in no soil moisture differences between drought and control treatments. Additional and more frequent samplings could help illuminate if or when microbial biomass and enzyme activity are affected by both drought and nutrient availability.
Included in
Biogeochemistry Commons, Other Ecology and Evolutionary Biology Commons, Soil Science Commons
The effects of imposed drought and nutrient availability on soil microbial biomass and enzyme activity in a long-term restored grassland
Restoring agricultural lands back to grassland aims to reverse many negative impacts of agriculture on the ecosystem including nutrient export from soil and depletion of soil carbon. Planting prairie on agricultural soil promotes recovery of soil microbial biomass and their enzymes, which create demand for nitrogen by microbes to reduce the rate of nutrient cycling and loss. A complicating factor in the development of a restored grassland the influence of several anthropogenic global changes including increasing frequency of drought and nutrient enrichment. Drought has been found to negatively affect microbial biomass, soil enzyme activity and nutrient cycling. Nutrient (often N) enrichment has been found to negatively affect C in the microbial biomass and soil enzyme activity while increasing N microbial biomass and soil enzyme activity. This research sought to investigate how drought and nutrient availability affected soil microbial biomass and soil enzyme activity in a long-term restored grassland. Only nutrient availability was found to affect either measurement, not drought or its interaction. Reduced N soils had the greatest microbial carbon biomass and enzyme activities compared to control and enriched N soils. Drought had no effects in the third year of imposed drought potentially due to timing of sampling in the field as the restoration plots had experienced severe rainfall within days of sampling. This resulted in no soil moisture differences between drought and control treatments. Additional and more frequent samplings could help illuminate if or when microbial biomass and enzyme activity are affected by both drought and nutrient availability.
