John W. Doran

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Soil health is the capacity of soil to function as a vital living system, within ecosystem and land-use boundaries, to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Anthropogenic reductions in soil health, and of individual components of soil quality, are a pressing ecological concern.(More)
Use of renewable N and C sources such as green manure (GM) and crop residues in rice-wheat cropping systems of South Asia may lead to higher crop productivity and C sequestration. However, information on measurements of gaseous N losses (N2O+N2) via denitrification and environmental problems such as N2O and CO2 production in rice-wheat cropping systems is(More)
Distribution of soil microbial biomass and potentially mineralizable nitrogen (PMN) in long-term tillage comparisons at seven sites in the United States varied with tillage management and depth in soil. Microbial biomass and PMN levels of no-tillage soils averaged 54% and 37% higher, respectively, than those in the surface layer of plowed soil. Biomass and(More)
corn–soybean cropping systems predominate. The effect of these cropping systems on indicators of soil quality Understanding long-term management effects on soil properties is only partially understood. Soil organic C has been is necessary to determine the relative sustainability of cropping systems. Soil physical, chemical, and biological properties were(More)
 The influence of fertilizer N applied through nitrate and ammoniacal sources on the availability of nitrate, supply of C, and gaseous N losses via denitrification (using acetylene inhibition technique) in a semiarid subtropical soil (Typic Ustochrepts) was investigated in a growth chamber simulating upland [60% water-filled pore space (WFPS)], nearly(More)
Runoff from a cow-calf pasture in eastern Nebraska was monitored for total coliforms (TC), fecal coliforms (FC), and fecal streptococci (FS) during 1976, 1977, and 1978. Bacteriological counts in runoff from both grazed and ungrazed areas generally exceeded recommended water quality standards. The FC group was the best indicator group of the impact of(More)
retaining crop residue on the soil surface to reduce erosion create an environment favorable for downy brome Adoption of reduced-tillage fallow systems in the western USA is because tillage operations are shallow (or eliminated) limited by winter annual grass weeds such as downy brome (Bromus and downy brome seeds are not buried deep enough to tectorum L.).(More)
water resources and enhancing soil quality (Wallace, 1994). An essential first step to the successful implemenTraditional sampling methods are inadequate for assessing the tation of site-specific management is the evaluation of interrelated physical, chemical, and biological soil properties responsible for variations in agronomic yield and ecological(More)