@article{raczkowski_mueller_busscher_bell_mcgraw_2012, title={Soil physical properties of agricultural systems in a large-scale study}, volume={119}, ISSN={["1879-3444"]}, DOI={10.1016/j.still.2011.12.006}, abstractNote={The extent to which findings from small-scale field studies can be used to make agricultural recommendations or management decisions is a concern because of natural influential processes that occur only at a large-scale. A large-scale field study was conducted to determine the effects of agricultural management systems on soil physical properties, including their spatial and temporal variations. Three replicates of the systems were based on soil type in an area that had been intensively mapped and were established in 1998 at the Center for Environmental Farming Systems, Goldsboro, NC. Agricultural management systems include five treatments which were best management practices (BMP: with subplots conventional tillage – BCT and no-tillage – BNT), organic crop production (OCP), integrated crop–animal (ICA), plantation forestry-woodlot (PFW), and abandoned-field succession (AFS). Soil physical properties of bulk density (Db), saturated hydraulic conductivity (Ksat), field capacity (FC), saturated water content (SWC), total porosity (TP), micro- and macroporosity (MicP, MacP), and water stable aggregation (WSA) were measured in multiple years within the period 1999–2007. The experimental methods successfully produced data with acceptable levels of variability, discernable soil property differences between systems, and unambiguous relationships between soil properties. Blocking areas with large portions of a diagnostic soil maintained the homogeneity of experimental plots and produced acceptable error terms in statistical procedures. The sampling scheme used prevented sample collection in previously sampled areas. Tilled systems BCT and OCP did not differ in soil physical properties and their properties remained rather constant with time. The BNT, PFW and AFS systems had similar properties with higher Db, lower TP, higher MicP and higher FC than tilled systems. The ICA sub-treatments developed a post-grazing higher Db, lower TP and lower MacP.}, journal={SOIL & TILLAGE RESEARCH}, author={Raczkowski, C. W. and Mueller, J. P. and Busscher, W. J. and Bell, M. C. and McGraw, M. L.}, year={2012}, month={Mar}, pages={50–59} } @article{reberg-horton_mueller_mellage_creamer_brownie_bell_burton_2011, title={Influence of field margin type on weed species richness and abundance in conventional crop fields}, volume={26}, ISSN={["1742-1705"]}, DOI={10.1017/s1742170510000451}, abstractNote={Abstract}, number={2}, journal={RENEWABLE AGRICULTURE AND FOOD SYSTEMS}, publisher={Cambridge University Press (CUP)}, author={Reberg-Horton, S. C. and Mueller, J. P. and Mellage, S. J. and Creamer, N. G. and Brownie, C. and Bell, M. and Burton, M. G.}, year={2011}, month={Jun}, pages={127–136} } @article{sydorovych_raczkowski_wossink_mueller_creamer_hu_bell_tu_2009, title={A technique for assessing environmental impact risks of agricultural systems}, volume={24}, ISSN={["1742-1713"]}, DOI={10.1017/S174217050999010X}, abstractNote={Abstract}, number={3}, journal={RENEWABLE AGRICULTURE AND FOOD SYSTEMS}, author={Sydorovych, Olha and Raczkowski, Charles W. and Wossink, Ada and Mueller, J. Paul and Creamer, Nancy G. and Hu, Shuijin and Bell, Melissa and Tu, Cong}, year={2009}, month={Sep}, pages={234–243} } @article{bell_raczkowski_2008, title={Soil property indices for assessing short-term changes in soil quality}, volume={23}, ISSN={["1742-1713"]}, DOI={10.1017/s1742170507001883}, abstractNote={Abstract}, number={1}, journal={RENEWABLE AGRICULTURE AND FOOD SYSTEMS}, author={Bell, M. C. and Raczkowski, C. W.}, year={2008}, month={Mar}, pages={70–79} } @article{tu_louws_creamer_mueller_brownie_fager_bell_hu_2006, title={Responses of soil microbial biomass and N availability to transition strategies from conventional to organic farming systems}, volume={113}, ISSN={["1873-2305"]}, DOI={10.1016/j.agee.2005.09.013}, abstractNote={Abstract Organic farming can enhance soil biodiversity, alleviate environmental concerns and improve food safety through eliminating the applications of synthetic chemicals. However, yield reduction due to nutrient limitation and pest incidence in the early stages of transition from conventional to organic systems is a major concern for organic farmers, and is thus a barrier to implementing the practice of organic farming. Therefore, identifying transition strategies that minimize yield loss is critical for facilitating the implementation of organic practices. Soil microorganisms play a dominant role in nutrient cycling and pest control in organic farming systems, and their responses to changes in soil management practices may critically impact crop growth and yield. Here we examined soil microbial biomass and N supply in response to several strategies for transitioning from conventional to organic farming systems in a long-term field experiment in Goldsboro, NC, USA. The transitional strategies included one fully organic strategy (ORG) and four reduced-input strategies (withdrawal of each or gradual reduction of major conventional inputs—synthetic fertilizers, pesticides (insecticides/fungicides), and herbicides), with a conventional practice (CNV) serving as a control. Microbial biomass and respiration rate were more sensitive to changes in soil management practices than total C and N. In the first 2 years, the ORG was most effective in enhancing soil microbial biomass C and N among the transition strategies, but was accompanied with high yield losses. By the third year, soil microbial biomass C and N in the reduced-input transition strategies were statistically significantly greater than those in the CNV (averaging 32 and 35% higher, respectively), although they were slightly lower than those in the ORG (averaging 13 and 17% lower, respectively). Soil microbial respiration rate and net N mineralization in all transitional systems were statistically significantly higher than those in the CNV (averagely 83 and 66% greater, respectively), with no differences among the various transition strategies. These findings suggest that the transitional strategies that partially or gradually reduce conventional inputs can serve as alternatives that could potentially minimize economic hardships as well as benefit microbial growth during the early stages of transition to organic farming systems.}, number={1-4}, journal={AGRICULTURE ECOSYSTEMS & ENVIRONMENT}, author={Tu, C and Louws, FJ and Creamer, NG and Mueller, JP and Brownie, C and Fager, K and Bell, M and Hu, SJ}, year={2006}, month={Apr}, pages={206–215} } @article{zhang_rui_tu_diab_louws_mueller_creamer_bell_wagger_hu_2005, title={Responses of soil microbial community structure and diversity to agricultural deintensification}, volume={15}, number={4}, journal={Pedosphere}, author={Zhang, W. J. and Rui, W. Y. and Tu, C. and Diab, H. G. and Louws, F. J. and Mueller, J. P. and Creamer, N. and Bell, M. and Wagger, M. G. and Hu, S.}, year={2005}, pages={440–447} }