Microbial responses and nitrous oxide emissions during wetting and drying of organically and conventionally managed soil under tomatoes |
| |
Authors: | Martin Burger Louise E. Jackson Erica J. Lundquist Dianne T. Louie Robin L. Miller Dennis E. Rolston Kate M. Scow |
| |
Affiliation: | (1) Department of Plant Sciences, University of California, Davis One Shields Avenue, Davis, CA 95616, USA;(2) Department of Land, Air and Water Resources, University of California, Davis One Shields Avenue, Davis, CA 95616, USA;(3) Present address: Lake County Winegrape Commission, P.O. Box 877, Lakeport, CA 95453, USA;(4) Present address: US Geological Survey, 6000 J St., Placer Hall, Sacramento, CA 95819, USA |
| |
Abstract: | The types and amounts of carbon (C) and nitrogen (N) inputs, as well as irrigation management are likely to influence gaseous emissions and microbial ecology of agricultural soil. Carbon dioxide (CO2) and nitrous oxide (N2O) efflux, with and without acetylene inhibition, inorganic N, and microbial biomass C were measured after irrigation or simulated rainfall in two agricultural fields under tomatoes (Lycopersicon esculentum). The two fields, located in the California Central Valley, had either a history of high organic matter (OM) inputs (“organic” management) or one of low OM and inorganic fertilizer inputs (“conventional” management). In microcosms, where short-term microbial responses to wetting and drying were studied, the highest CO2 efflux took place at about 60% water-filled pore space (WFPS). At this moisture level, phospholipid fatty acids (PLFA) indicative of microbial nutrient availability were elevated and a PLFA stress indicator was depressed, suggesting peak microbial activity. The highest N2O efflux in the organically managed soil (0.94 mg N2O-N m−2 h−1) occurred after manure and legume cover crop incorporation, and in the conventionally managed soil (2.12 mg N2O-N m−2 h−1) after inorganic N fertilizer inputs. Elevated N2O emissions occurred at a WFPS >60% and lasted <2 days after wetting, probably because the top layer (0–150 mm) of this silt loam soil dried quickly. Therefore, in these cropping systems, irrigation management might control the duration of elevated N2O efflux, even when C and inorganic N availability are high, whereas inorganic N concentrations should be kept low during times when soil moisture cannot be controlled. |
| |
Keywords: | Microbial respiration Carbon dioxide efflux Denitrification Acetylene block Phospholipid fatty acids |
本文献已被 SpringerLink 等数据库收录! |
|