ARS | Publication request: Soil and water conservation via reduced tillage in the GA Piedmont

Submitted to: Southern Conservation Tillage Systems Conference
Publication Type: Proceedings
Publication Acceptance Date: August 24, 2008
Publication Date: August 25, 2008
Citation: Truman, C.C., Franklin, D.H., Schomberg, H.H., Endale, D.M. 2008. Soil and water conservation via reduced tillage in the GA Piedmont. In: D.M. Endale (ed) Proceedings 30th Southern Agricultural Systems Conference, July 29-31, 2008, Tifton, Georgia. p74-78.

Interpretive Summary: Piedmont soils have historically been managed under conventional tillage practices and are susceptible to runoff and sediment losses. Because of row-crop production history, Piedmont soils, especially the Cecil series, has experienced accelerated erosion and subsequent degradation of its intrinsic soil properties, productivity, and overall environmental quality. Conservation tillage systems offer an effective, viable management tool for row crop production and soil and water conservation. Furthermore, current agricultural water issues and the need to reduce input costs in farming operations add importance to making sound irrigation and management decisions to ensure efficient water use, natural resource conservation, and on-farm profitability. We quantified infiltration, runoff, and sediment losses from a Cecil sandy loam managed under conventional- (CT) and no- till (NT) systems. CT plots had 6 X more runoff and 11.1 X more soil loss than NT plots. Compared to NT plots, CT plots had 4.5 X more splash sediment and were 4.5 X more susceptible to surface sealing. Assuming that evapotranspiration was 0.2 in/day and all infiltration was available to plants, CT plots had 4.9 days of water for crop use; whereas NT plots had 10.2 days of water for crop use. This difference (5.3 days of water for crop use) would result in a producer utilizing a NT system to irrigate ~ 2.1 X less than a producer utilizing a CT system to produce the same crop, a 50% water and energy savings in irrigation cost.

Technical Abstract: Piedmont soils have historically been managed under conventional tillage practices and are susceptible to runoff and sediment losses. Because of row-crop production history, Piedmont soils, especially the Cecil series, has experienced accelerated erosion and subsequent degradation of its intrinsic soil properties, productivity, and overall environmental quality. Conservation tillage systems offer an effective, viable management tool for row crop production and soil and water conservation. Furthermore, current agricultural water issues and the need to reduce input costs in farming operations add importance to making sound irrigation and management decisions to ensure efficient water use, natural resource conservation, and on-farm profitability. We quantified infiltration, runoff, and sediment losses from a Cecil sandy loam managed under conventional- (CT) and no- till (NT) systems with commercial fertilizer and poultry litter fertilizer sources. A total of 12 field plots received 60 min of simulated rainfall (target intensity=2 in/h). Fertilizer source sub-treatment did not significantly affect hydrology and erosion parameters. CT plots had 2.2 X less infiltration and 6.0 X more runoff than NT plots, even though NT plots had 2.5 X higher soil water contents. NT and CT plots had 90% and 45% (2 X difference) of the simulated rainfall infiltrated; whereas NT and CT plots had 10% and 55% (5.5 X difference) of the simulated rainfall runoff. CT plots had 11.1 X more soil loss than NT plots. Maximum runoff rate for CT plots was 3.8 X greater than that for NT plots; maximum soil loss rate for CT plots was 9.4 X greater than that for NT plots. Compared to NT plots, CT plots had 4.5 X more splash sediment and were 4.5 X more susceptible to surface sealing. Assuming that evapotranspiration was 0.2 in/day and all infiltration was available to plants, CT plots had 4.9 days of water for crop use; whereas NT plots had 10.2 days of water for crop use. This difference (5.3 days of water for crop use) would result in a producer utilizing a NT system to irrigate ~ 2.1 X less than a producer utilizing a CT system to produce the same crop, a 50% water and energy savings in irrigation cost.