|Title||Potential environmental controls on nitrogenase activity in biological crusts of the northern Chihuahuan Desert|
|Publication Type||Journal Article|
|Year of Publication||2002|
|Authors||Hartley AE, Schlesinger WH|
|Journal||Journal of Arid Environments|
|Keywords||article, articles, journal, journals, nitrogenase activity, soil crust, biological|
We used the acetylene reduction assay to analyse soil nitrogenase activity at the Jornada Long-Term Ecological Research site (northern Chihuahuan Desert, New Mexico, U.S.A.). A three-day irrigation and fertilization experiment showed that water and carbon (glucose) enhanced nitrogenase activity, while NH4NO3 reduced activity. Micronutrient (Mo, Fe, Co) and phosphorus fertilization had no significant effect. A survey of Jornada Basin soils did not reveal an inverse relationship between nitrogenase activity and the ratio of available nitrogen (N) to phosphorus (P), as hypothesized; however, the highest rates of nitrogenase activity were detected in tarbush floodplain soils with a low ratio of available N to P. These findings suggest that labile carbon and inorganic N may exert a stronger control on nitrogenase activity than phosphorus or micronutrient levels.
|Reprint Edition||In File (03/25/03)|