Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2002
Publication Date: 7/1/2004
Citation: Liebig, M.A., Tanaka, D.L., Wienhold, B.J. 2004. Tillage and cropping effects on soil quality indicators in the northern great plains. Soil & Tillage Research. 78(2):131-141. Interpretive Summary: Farming practices in the Northern Great Plains must possess a resilient soil resource in order to be sustainable. Results from a long-term cropping systems experiment established in 1984 in central North Dakota indicated that soil in a continuous crop, no-till management practice was improved with respect to its ability to provide a source for plant nutrients, withstand erosion, and facilitate water transfer as compared to a crop-fallow, conventional tillage management practice. These results were supported by observations of more soil organic matter, greater aggregate stability, and faster water infiltration rates in the continuous crop, no-till practice. Results from a long-term experiment established in 1993 in the same region were less definitive, yet supported the notion that continuous cropping and minimum tillage were creating a favorable plant growth environment over time. Results from both experiments confirm that farmers in the Northern Great Plains can improve soil quality and agricultural sustainability by adopting production systems that employ continuous cropping practices with reduced tillage management.
Technical Abstract: The extreme climate of the Northern Great Plains necessitates cropping systems in the region to possess a resilient soil resource in order to be sustainable. This paper summarizes the effects of tillage, crop sequence, and cropping intensity on soil quality indicators for two long-term cropping system experiments (est. 1984 and 1993) in central North Dakota. Soil properties considered as indicators of soil quality were evaluated in spring 2001 in both experiments at depths of 0 to 7.5, 7.5 to 15, and 15 to 30 cm. For the experiment established in 1984, a continuous crop, no-till system possessed significantly more soil organic C, particulate organic matter C, potentially mineralizable N, and microbial biomass C, as well as greater aggregate stability and faster infiltration rates relative to a crop-fallow, conventional tillage system for the surface 7.5 cm depth. Thus, soil from the continuous crop, no-till system was improved with respect to its ability to provide a source for plant nutrients, withstand erosion, and facilitate water transfer. Soil properties were affected less by management practices in the experiment established in 1993, although significantly more particulate organic matter, potentially mineralizable N, and microbial biomass C was observed under continuous cropping or minimum tillage as compared to crop sequences with fallow or no-till. Results from both experiments confirm that farmers in the Northern Great Plains can improve soil quality and agricultural sustainability by adopting production systems that employ intensive cropping practices with reduced tillage management.