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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Publications at this Location » Publication #299029
Title: Crop, tillage, and landscape effects on near-surface soil quality indices in Indiana

Author
item Hammac Ii, Warren
item Stott, Diane
item Karlen, Douglas
item Cambardella, Cynthia

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2016
Publication Date: 10/1/2016
Citation: Hammac II, W.A., Stott, D.E., Karlen, D.L., Cambardella, C.A. 2016. Crop, tillage, and landscape effects on near-surface soil quality indices in Indiana. Soil Science Society of America Journal. 80:1638-1652. doi:10.2136/sssaj2016.09.0282.

Interpretive Summary: Soil quality is considered a link between land management and the quality of adjacent water bodies. We conducted a soil quality assessment within the Cedar Creek Watershed, a part of the larger St. Joseph River Watershed that drains into the Western Lake Erie Basin in northwestern Indiana. The Soil Management Assessment Framework (SMAF) with ten soil quality indicators was used for the assessment. Inherent soil (soil type and texture, slope of the hillside, mineralogy of the soil clay) and environmental characteristics (annual temperature and rainfall and season of sampling) are considered during the scoring process. Bulk density (BD), macroaggregate stability (MAS), pH, electrical conductivity (salt content; EC), soil organic carbon (SOC), microbial biomass carbon (MBC), potentially mineralizable nitrogen (NMIN), ß-glucosidase (BG) activity (involved in cellulose degradation) and extractable phosphorus (P) and potassium (K) were quantified and scored. Carbon mineralization and additional micronutrient concentrations were also measured. Soils in this watershed had mean soil quality indices (SQIs) indicating they were performing at 81% (range: 60 to 94%) of optimum within the 0 to 15-cm depth. Physical (BD, MAS), chemical (pH, EC) and nutrient (P, K) indices were high, averaging 88, 97 and 100% of optimum, respectively. The biological indicators (SOC, MBC, BG, NMIN) had the lowest scores, averaging 61% of optimum. Landscape position (hilltop, mid-slope, toe-slope) generally did not impact overall indicator scores, although biological indicator scores were significantly higher within toe-slope positions than at summits or mid-slopes. Perennial grass cropping systems scored higher than either no-till or chisel/disk systems management systems that are used for row crops. The tillage systems were not significantly different from one another. Corn-based cropping systems scored lower than the perennial grass systems, while legume-based systems fell in-between. The legume-based systems included: continuous (3-yr) soybean, soybean with alfalfa, and corn with alfalfa, but excluded the more typical 2-yr corn-soybean rotations (considered under corn-based systems). For this watershed, crop selection had greater impact on soil quality than tillage.

Technical Abstract: Soil quality is considered a link between land management and the quality of adjacent water bodies. We conducted a soil quality assessment within the Cedar Creek Watershed, a part of the larger St. Joseph River Watershed that drains into the Western Lake Erie Basin in northwestern Indiana. The Soil Management Assessment Framework (SMAF) with ten soil quality indicators was used for the assessment. Inherent soil and environmental characteristics are considered during the scoring process. Bulk density (Db), macroaggregate stability (MAS), pH, electrical conductivity (EC), soil organic C (SOC), microbial biomass C (MBC), potentially mineralizable N (Nmin), ß-glucosidase activity (BG) and extractable P and K were quantified and scored. Carbon mineralization and additional nutrient concentrations were also measured. Soils in this watershed had mean soil quality indices (SQIs) indicating they were performing at 81% (range: 60 to 94%) of optimum within the 0 to 15-cm depth. Physical, chemical and nutrient indices were high, averaging 88, 97 and 100% of optimum, respectively. The biological indicators had the lowest scores, averaging 61% of optimum. Landscape position generally did not impact overall indicator scores, although biological indicator scores were significantly higher within toe-slope positions than at summits or mid-slopes. Perennial cropping systems scored higher than either no-till or chisel/disk systems, which were not significantly different. Corn (Zea mays L.) based cropping systems scored lower than perennial grass, while legume-based systems (excluding 2-yr corn-soybean [Glycine max (L.) Merr.] rotations) fell in-between. For this watershed, crop selection had greater impact on soil quality than tillage.