Soil Response to Long-Term Cropping Systems on an Argiustoll in the Central Great Plains

Development or identification of cropping systems that conserve soil and water, sequester soil organic C (SOC), and improve soil productivity is a high research priority, particularly in semiarid regions. We assessed the impacts of 33-yr cropping systems on near-surface soil structural, compaction, and hydraulic properties and their relationships with SOC concentration on a nearly level Crete silty clay loam (fine, smectitic, mesic Pachic Argiustoll) in the central Great Plains. Five cropping systems (sorghum [Sorghum bicolor (L.) Moench]-fallow [SF], continuous sorghum [SS], winter wheat [Triticum aestivum L.]-sorghum-fallow [WSF], wheat-fallow [WF], and continuous wheat [WW]) under reduced tillage (RT) and no-till (NT) were studied. Cropping systems significantly impacted soil properties. Wet aggregate stability and aggregate water repellency in WW were two to five times geater than in other rotations for the 0- to 2.5-cm soil depth. The WW and WSF retained 10 to 16% more water than SF between 0 and -3 kPa matric potentials under NT The WW reduced bulk density (rho(b)) and increased cumulative water infiltration over other rotations under NI The WW increased SOC concentration over all other rotations under NT and SF and SS under RT in the 0- to 2.5-cm depth. The SF affected soil properties more adversely than WF. Wet aggregate stability, water repellency, total porosity, cumulative water infiltration, and soil water retention increased while rho(b) decreased with an increase in SOC concentration. Wet aggregate stability increased with an increase in aggregate water repellency (r > 0.80, P < 0.001). Overall, intensification of cropping systems such as WW coupled with NT improved soil physical properties and increased SOC concentration.