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ARS Home » Southeast Area » Tifton, Georgia » Southeast Watershed Research » Research » Publications at this Location » Publication #137757
Title: TILLAGE EFFECTS ON INTERRILL ERODIBILITY OF TWO ALABAMA SOILS

Author
item Truman, Clinton
item SHAW, J. - AUBURN UNIV.
item REEVES, D. - USDA-MS (AUBURN)

Submitted to: Annual Southern Conservation Tillage Conference for Sustainable Agriculture
Publication Type: Proceedings
Publication Acceptance Date: 6/2/2002
Publication Date: 6/24/2002
Citation: TRUMAN, C.C., SHAW, J.N., REEVES, D.W. TILLAGE EFFECTS ON INTERRILL ERODIBILITY OF TWO ALABAMA SOILS. ANNUAL SOUTHERN CONSERVATION TILLAGE CONFERENCE FOR SUSTAINABLE AGRICULTURE. PP. 288-294. 2002.

Interpretive Summary: Alabama soils have been managed under conventional tillage practices and most are considered highly erodible. Conservation tillage is effective in reducing soil loss. We quantified soil loss and calculated interrill erodibilities (Ki) for two Alabama soils managed under conventional- (CT) and no-till (NT) systems. We evaluated NT with and without paratilling (+P, -P) and with and without surface cover (rye) (C, NC). Four tillage system treatments evaluated were conventional tillage without fall paratilling and without rye cover (CT-P, NC), no-till without fall paratilling and without cover (NT-P, NC), no-till without fall paratilling and with cover (NT-P, C), and no-till with fall paratilling and cover (NT+P, C). Duplicate 1-m^2 plots established on each tillage treatment were exposed to simulated rainfall (50 mm/h for 2 h). Runoff and soil loss were controlled by either residue cover or paratilling. Erodibility values calculated based on rainfall intensity (Kii) ranged from 0.14-4.03, and those calcultated based on runoff energy (Kiq) ranged from 0.24-5.12. For both soils, runoff, soil loss, and Ki values were greatest and infiltration was lowest for CT-P, NC plots (worst-case scenario). Runoff, soil loss, and Ki values were lowest and infiltration was highest for NT+P, C plots (best-case scenario). For both soils, Ki values for CT-P, NC plots were 10-20 fold greater than those for NT+P, C plots. The CT-P, NC treatment represents the greatest potential for runoff and soil loss. Surface residue management through conservation tillage coupled with paratilling is the best system to promote infiltration and reduced runoff, soil loss, and Ki for soils in the Coastal Plain and Tennessee Valley regions of Alabama.

Technical Abstract: Alabama soils have been managed under conventional tillage practices and most are considered highly erodible. Conservation tillage is effective in reducing soil loss. The objective of this study was to quantify soil loss and calculate interrill erodibilities (Ki) for loamy sand and silt loam soils managed under conventional- (CT) and no-till (NT) systems. We also evaluated NT with and without paratilling (+P, -P) and with and without surface cover (rye) (C, NC). Four tillage system treatments evaluated were conventional tillage without fall paratilling and without rye cover (CT-P, NC), no-till without fall paratilling and without cover (NT-P, NC), no-till without fall paratilling and with cover (NT-P, C), and no-till with fall paratilling and cover (NT+P, C). Duplicate 1-m^2 plots established on each tillage treatment were exposed to simulated rainfall (50 mm/h for 2 h). Runoff and soil loss were measured continuously from each plot (slope=1%). At E.V. Smith, runoff and soil loss were controlled by residue cover. Kii values ranged from 0.14-2.87, and Kiq ranged from 0.24-4.34. Runoff, soil loss, and Kii (0.29-4.03) and Kiq (0.48-5.12) values at TN Valley were controlled by paratilling. At both sites, runoff, soil loss, and Ki values were greatest and infiltration was lowest for CT-P, NC plots (worst-case scenario). Runoff, soil loss, and Ki values were lowest and infiltration was highest for NT+P, C plots (best-case scenario). For both soils, Ki values for CT-P, NC plots were 10-20 fold greater than those for NT+P, C plots. The CT-P, NC treatment represents the greatest potential for runoff and soil loss. Surface residue management through conservation tillage coupled with paratilling is the best system to promote infiltration and reduced runoff, soil loss, and Ki for soils in the Coastal Plain and Tennessee Valley regions of Alabama.