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ARS Home » Southeast Area » Tifton, Georgia » Southeast Watershed Research » Research » Publications at this Location » Publication #119202
Title: TILLAGE EFFECTS ON RAINFALL PARTITIONING AND SEDIMENT YIELD FROM AN ULTISOL IN CENTRAL ALABAMA

Author
item Truman, Clinton
item SHAW, J - AUBURN UNIVERSITY
item Reeves, Donald

Submitted to: Journal of Soil and Water Conservation Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2003
Publication Date: 2/1/2005
Citation: Truman, C.C., Shaw, J.N., Reeves, D.W. 2005. Tillage effects on rainfall partitioning and sediment yield from an ultisol in central Alabama. Journal of Soil and Water Conservation Society 60(2):89-98(2005)

Interpretive Summary: Conservation tillage systems have significant potential as a management tool for row crop production, especially on erosion-prone sandy surface soils of the Coastal Plain region (USA). We quantified rainfall partitioning and sediment delivery from a loamy sand soil managed under conventional-till (CT) and no-till (NST) systems, and also with and without tparatilling and surface residue. Plots (1 m x 1 m) established on the loam sand soil were exposed to simulated rainfall for two hours with a target intensity of 50 mm/h. Runoff and sediment delivery were continuously measured. Compared to CT plots, NST plots had about 2 times less runoff and 3 times less sediment delivery. This corresponds to 21 and 22% more of the total rainfall running off and sediment lost from CT plots compared to NST plots, respectively. Removing residue increased runoff sediment losses by 5- and 7-fold for NST plots and 2.5 and 1.5 times for CT plots, respectively, resulting in 18% more runoff as a percentage of rainfall for NST plots and 25% more runoff for CT plots. Paratilling reduced bulk density values in the top 12 cm of soil, and reduced runoff by at least 37% for CT and NST plots. NST plots had more surface residue (6148 vs. 207 kg/ha), higher organic carbon contents (24% more overall and 91% more in the 0-1 cm soil layer), more water stable aggregates (21% more in the 0-3 cm soil layer), and increased soil strength (3.6 times greater in the 1.5 cm soil layer) than CT plots. Residue management by reduced tillage systems improved soil quality, promoted infiltration and increased plant available water,thus conserves soil and water resources by reducing runoff and sediment delivery.

Technical Abstract: Conservation tillage systems have significant potential as a management tool for row crop production, especially on sandy surface soils of the Coastal Plain region (USA). We quantified rainfall partitioning and sediment delivery from a loamy sand - sandy loam soil complex managed under conventional-till, no-till, and paratill systems. Plots (1 m x 1 m) established on the soil complex in central Alabama were managed under conventional (CT) and conservation (NST)tillage systems, and exposed to simulated rainfall for two hours with an intensity of 50 mm/h. Runoff and sediment delivery were continuously measured. Compared to CT plots, NST plots had about 2 times less runoff and 3 times less sediment delivery. This corresponds to 21 and 22% more of the total rainfall running off and sediment lost from CT plots compared to NST plots, respectively. Removing residue increased runoff and sediment losses by 5- and 7-fold for NST plots sand 2.5 and 1.5 times for CT plots, respectively, resulting in 18% more runoff as a percentage of rainfall for NST plots and 25% more runoff for CT plots. Paratilling reduced bulk density values in the top 12 cm of soil, and reduced runoff by at least 37% for CT and NST plots. NST plots had more surface residue (6148 vs. 207 kg/ha), higher organic carbon contents (24% more overall and 91% more in the 0-1 cm soil layer), 21% more water stable aggregates in the 0-3 cm soil layer), and 3.6 times greater soil strength in the 1.5 cm soil layer than CT plots. Residue management via reduced tillage systems promoted infiltration and increased plant available water, thus conserved soil and water resources by reducing runoff and sediment delivery.