Soil Nitrogen Manipulation Study – Kurt Klasson

This study was set up in May 2003 to test the effect of encorporated sawdust on soil nitrogen levels and plant community composition. Six of the twelve experimental plots had 500 mg/ square meter of fine grained sawdust added to each of them at the beginning of the study. We hypothesize that this sawdust addition will increase the carbon: nitrogen ratio of the soil. High carbon: nitrogen ratios approximate natural prairie soil conditions. These soil conditions have previously been shown to give native prairie plants a competitive advantage against invasive species, which typically require higher levels of soil nitrogen. All twelve plots were seeded with a mixture of prairie plants. The growth of these prairie plants as well as that of weed species will be compared between treatment plots (those treated with sawdust), and the control plots, which were not amended with sawdust. Our prediction is that the treatment plots will have a higher percentage of prairie plants than the control plots.