Journal Article

Strength properties and organic carbon of soils in the North Appalachian region

Blanco-Canqui, H, Izaurralde, R.C, Owens, L.B, Post, W.M, Lal, R

2005

Overview

Soil strength influenced by management and soil properties controls plant growth, root development, and soil-moisture relations. The impact of textural and structural parameters on soil strength is moderated by soil organic C (SOC) concentration. Therefore, the objectives of this study were to assess differences in soil strength and SOC concentration in watersheds under long-term (>15 yr) management practices in the North Appalachian region on a predominantly Typic Hapludults on undulating slopes (>6% slope). Seven watersheds without field replication under moldboard plow (MP), chisel plow, disk with beef cattle manure (DiskM), no-till with beef cattle manure (NTm), no-till with no beef cattle manure (NTnm), pasture, and forest were studied. Cone index (CI), shear strength, bulk density (rho(b)), volumetric moisture content (theta(v)), and SOC concentration were determined at the summit, backslope, and footslope landscape positions at the 0- to 10-, 10- to 20-, and 20- to 30-cm depths. The SOC concentration was slightly higher at the footslope than at the summit position in the cultivated watersheds. The rho(b) was lower at the footslope than at the summit in NTm (1.22 vs. 1.42 Mg m(-3)) and chisel (1.34 vs. 1.47 Mg m(-3)) treatments. Forest had the lowest CI (0.19 MPa), shear strength (6.11 kPa), and rho(b) (0.93 Mg m(-3)) and the highest SOC concentration (62.7 g kg(-1)), whereas MP had the highest CI (0.67 MPa), shear strength (25.5 kPa), rho(b) (1.44 Mg m(-3)), and the lowest SOC concentration (13.6 g kg(-1)) in the 0- to 10-cm depth (P < 0.01). The SOC concentration in NTm was 1.7 times higher than that in NTnm, and both no-till treatments had lower rho(b) (<1.21 Mg m(-3)) than MP (1.44 Mg m(-3)) at 0- to 10-cm depth (P < 0.01). Manuring decreased both CI and shear strength, but increased SOC concentration. The rho(b), theta(v), and SOC concentration were potential predictors of CI; whereas rho(b) and SOC concentration were of shear strength (r2 > 0.42; P < 0.01). Results show that landscape positions had small effect, but management, particularly manuring, had large and significant effects on soil strength and SOC concentration.

• Publisher: Soil Science Society,Soil Science Society of America,American Society of Agronomy
• Subject: Agronomy. Soil science and plant productions / Appalachian region / Beef cattle / Biological and medical sciences / carbon / Cattle manure / Chemical, physicochemical, biochemical and biological properties / Earth sciences / Earth, ocean, space / Exact sciences and technology / Fundamental and applied biological sciences. Psychology / Hapludults / land use / landscape position / Manures / Moisture content / Ohio / Organic carbon / Organic matter / Parameter estimation / Pasture / Physical properties / Physics, chemistry, biochemistry and biology of agricultural and forest soils / Plant growth / Root development / soil depth / soil management / soil organic matter / soil physical properties / Soil properties / Soil science / Soil sciences / Soil strength / Soils / Structure, texture, density, mechanical behavior. Heat and gas exchanges / Surficial geology / Tillage / Watersheds