Topsoil Properties as Affected by Tillage Systems in the Rolling Pampa Region of Argentina

• Published in: Soil Science Society of America journal Vol. 73; no. 4; pp. 1242 - 1250
• Main Authors: Alvarez, Carina R, Taboada, Miguel A, Gutierrez Boem, Flavio H, Bono, Alfredo, Fernandez, Patricia L, Prystupa, Pablo
• Format: Journal Article
• Language: English
• Published: Madison Soil Science Society 01.07.2009; Soil Science Society of America; American Society of Agronomy
• Subjects: aggregate stability; Agronomy. Soil science and plant productions; Argentina; Biological and medical sciences; bulk density; Carbon; Clay loam; clay loam soils; conventional tillage; Cropping systems. Cultivation. Soil tillage; Earth sciences; Earth, ocean, space; Evolution; Exact sciences and technology; Farmers; Fossil fuels; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grassland soils; Infiltration; infiltration (hydrology); Infiltration rate; Loam soils; no-tillage; Organic matter; Pampas region; pampas soils; Physical properties; Principal components analysis; Silt loam; silt loam soils; Soil erosion control; soil management; soil morphological features; Soil organic matter; soil penetration resistance; Soil physical properties; Soil science; soil structure; soil texture; Soil tillage; Soils; Surficial geology; Tillage; Tillage. Tending. Growth control; Topsoil; Water conservation; Argentina; Pampas region; South America; Argentina, Pampa; Cultural practice; soil management; grasslands; Soil tillage; Top soil; temperate zone; Soil science; Earth science; Influence factor; properties; System
• ISSN: 0361-5995; 1435-0661
• DOI: 10.2136/sssaj2008.0246

Improved topsoil structural quality is expected under no-till farming, but soil physical constraints can develop under continuous no-till. Our objectives were: to evaluate the properties of loam, silty loam, and silty clay loam soils under various management practices on a regional scale; to clarify the relationship between soil organic matter pools and soil physical properties; and to find a minimum set of topsoil properties to characterize trends established by tillage. Thirty-nine loam, silty loam, and silty clay loam soils were sampled from cropped fields managed using conventional tillage (CT) and no-till (NT) as well as six undisturbed soils (uncropped). The A horizon thickness did not differ among soil textural groups and was 4 cm thicker in uncropped soils. Total and particulate organic C were significantly affected by management (uncropped > CT = NT, P < 0.001). Soil structural instability of uncropped soils (0.317 mm) differed from CT soils (0.723 mm) but not from NT soils (0.573 mm). Soil structural instability was negatively related to total and particulate organic C, and no relation was found with the resistant organic C pool. Water infiltration rate was the only topsoil property affected by a significant texture x management interaction. Lower infiltration rates in NT silty soils were caused by platy structural forms with horizontal pores. Soil penetration resistance (0-5 cm) was 0.77 MPa higher in NT than in CT soils. A minimum set of topsoil properties to evaluate tillage management includes structural instability, total or particulate organic C, infiltration rate, and penetration resistance.