Nitrogen Fixation by Algae in Fescuegrass Soil Crusts1
- Gudiogopuram B. Reddy and
- Joel Giddens2
Soil crusts and subsoil samples of different ages of tall fescuegrass (Festuca arundinacea Schreb.) were collected and analyzed for N, C, and acetylene reduction. Total N and C in the crust was 0.18% and 2.76%, respectively, in 4-year old soil crust as compared to 0.06% and 0.67%, respectively, in fallow soil. The amount of acetylene reduction after 5 days' incubation was 13.77 µmole/flask (9.6 cm2) for the 4-year-old sod crust compared to 3.06 µmole/flask for the fallow control. Ammonium nitrate reduced and liming increased N fixation in the crust. Nitrogen fixation in the crust was highest at 55% shade. Blue-green algae present in the crust were Anabaena, Nostoc, Syctonema, and Oscillatoria. Greater nitrogen fixation occurred when moss (Bryum sp.) was present in crust.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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