Data from: Tillage and cropping effects on soil quality indicators in the northern Great Plains

Cropping systems in the northern Great Plains must possess a resilient soil resource to be sustainable. Detecting the effects of management on soil properties in this region is challenging, frequently requiring the use of long-term experiments. A study was conducted to quantify the interactive effects of tillage, crop sequence, and cropping intensity on soil properties for two long-term cropping system experiments in the northern Great Plains. The experiments were established in 1984 and 1993 on the Area IV Soil Conservation Districts Cooperative Research Farm near Mandan, North Dakota USA. Soil physical, chemical, and biological properties considered as indicators of soil quality were evaluated in spring 2001 in both experiments. Samples were collected from the 0-30 cm depth in increments of 0-7.5, 7.5-15, and 15-30 cm using a step-down probe. As a contrast to treatments in the 1984 experiment, samples were collected from a nearby moderately grazed pasture with the same soil type. Soil samples were evaluated for soil bulk density, electrical conductivity, soil pH, soil nitrate-nitrogen, soil organic carbon, total soil nitrogen, particulate organic matter carbon and nitrogen, potentially mineralizable nitrogen, and microbial biomass carbon and nitrogen. Supplemental soil assessments of water-stable aggregation and infiltration rate were conducted in the 1984 experiment, while stover biomass production in the 1993 experiment complemented soils data. Laboratory methods followed accepted protocols. Particulate organic matter was measured with two methods. For the 1984 experiment, material retained on a 0.053 mm sieve was collected and analyzed by dry combustion for carbon and nitrogen content, while a weight loss-on-ignition method was used for 0.053–0.5 and 0.5–2.0 mm size fractions for the 1993 experiment. Data may be used to better understand soil property responses to crop rotation and tillage practices under rainfed conditions within a semiarid continental climate. Applicable USDA soil types include Temvik, Wilton, Grassna, Linton, Mandan, and Williams.