Author
Truman, Clinton | |
Nuti, Russell |
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/10/2008 Publication Date: 3/21/2009 Citation: Truman, C.C., Nuti, R.C. 2009. Improved Water Capture and Erosion Reduction Through Furrow Diking. Agricultural Water Management. 96:1071-1077. Interpretive Summary: Crop production in the Southeast is water limited. Increased water capture would efficiently improve natural water use and reduce supplemental irrigation amounts and other input costs, thus improving producer’s profit margin. Furrow diking is a management practice that creates surface storage basins between crop rows to catch and retain rainfall and/or irrigation water. We quantified water capture and erosional characteristics of furrow diking by comparing infiltration, runoff, and soil loss from diked and non-diked tilled systems. Treatments included: Diked tillage vs. conventional tillage; Diked tillage with and without shank. Compared to conventional tillage, diked tillage increased infiltration and plant available water estimates by as much as 26%, and decreased runoff and soil loss by as much as 43% and 2.8-fold, respectively. Based on $12 per acre*inch to pump irrigation water and $7.50/A for furrow diking, a producer would recover 60% of his furrow diking cost by saving the first acre*in of water and 100% of his furrow diking cost by saving 1.25 acre*inches of water. Furthermore, based on 2006 and 2007 data for diked and non-diked cotton, 3.3 irrigations or 3.3 inches of water were saved per year on average, thus the producer would save $32 per acre beyond his diking cost. Diked tillage with a shank (best-case) treatment had about 90% more infiltration and days of water for crop use based on a 2 inch rainfall, 67% more days of water for crop use based on a 1 inch irrigation, 3-fold less runoff, and 3-fold less soil loss than conventional tillage without a shank treatment (worst-case). Water and financial savings associated with diked tillage systems does not include the environmental benefits of the reduction in natural resource consumption, runoff, soil erosion, and any associated contaminants. The diked tillage system coupled with an in-row shank is a cost-effective management practice for producers in Georgia and the Southeast that has a positive and significant impact on natural resource conservation, producer profit margins, and environmental quality. Technical Abstract: Crop production in the Southeast is water limited. Increased water capture would efficiently improve natural water use and reduce supplemental irrigation amounts and other input costs, thus improving producer’s profit margin. Furrow diking creates surface storage basins between crop rows to catch and retain rainfall and/or irrigation water. We quantified water capture and erosional characteristics of furrow diking by comparing infiltration (INF), runoff (R), and soil loss (E) from diked (DT) and non-diked tilled systems. A 2-year study (Faceville loamy sand) was conducted near Dawson, GA with DT and non-diked conventional tilled (CT) systems managed to cotton. Treatments included: DT vs. CT; DT with and without shank (+/- S); and time after planting when DT was performed (0, 60 days after planting). Simulated rainfall (50 mm/h for 1 h) was applied to all plots (2x3 m). Runoff and soil loss were measured from 6m2 rainfall simulator plots (slope=1%). Compared to CT, DT increased INF and plant available water (PAW) estimates by as much as 26%, and decreased R and E by as much as 43% and 2.8-fold, respectively. Based on $12 per acre*inch to pump irrigation water and $7.50/A for furrow diking, a producer would recover 60% of his furrow diking cost by saving the first acre*in of water and 100% of his furrow diking cost by saving 1.25 acre*inches of water. Compared to DT at planting (DT0), DT at 60 days after planting (DT60) increased INF and PAW estimates by as much as 26%, and decreased R and E by as much as 2.3-fold and 33%, respectively. Compared to DT-S, DT+S increased INF and PAW estimates by as much as 23%, and decreased R and E by as much as 61% and 2.2-fold, respectively. Compared to crusted soil conditions at DAP=60, simulating rainfall on a freshly tilled seedbed condition (DAP=0) increased INF by as much as 69%, decreased R by as much as 69%, and increased E by as much as 27%. DT60+S+RF60 plots (best case) had about 90% more INF and days of water for crop use based on a 50 mm rainfall, 67% more days of water for crop use based on a 25 mm irrigation, 3-fold less R, and 3-fold less E than CT-S+RF60 plots (worst case). Water and financial savings associated with DT systems do not include the environmental benefits of the reduction in natural resource consumption, runoff, soil erosion, and any associated contaminants. The DT+S system is a cost-effective management practice for producers in Georgia and the Southeast that has a positive and significant impact on natural resource conservation, producer profit margins, and environmental quality. |