Improved water capture and erosion reduction through furrow diking

Crop production in Georgia and the Southeastern U.S. can be limited by water; thus, supplemental irrigation is often needed to sustain profitable crop production. Increased water capture would efficiently improve water use and reduce irrigation amounts and other input costs, thus improving producer's profit margin. We quantified water capturing and erosional characteristics of furrow diking by comparing runoff (R) and soil loss (E) from furrow diked (DT) and non-furrow diked tilled (CT) systems. A field study (Faceville loamy sand, Typic Kandiudult) was established (2006 and 2007) near Dawson, GA with DT and CT systems managed to irrigated cotton (Gossypium hirsutum L.). Treatments included: DT vs. CT; DT with and without shank (+/- S); and rainfall simulation performed (0, 60 days after tillage, DAT). Simulated rainfall (50mmh-1 for 1h) was applied to all 2mx3m plots (n=3). All runoff and E were measured from each flat, level sloping 6-m2 plot (slope=1%). Compared to CT, DT decreased R and E by 14-28% and 2.0-2.8 times, respectively. Compared to DT-S, DT+S decreased R and E by 17-56% and 26% to 2.1 times, respectively. Compared to sealed/crusted soil conditions at 60 DAT, simulating rainfall on a freshly tilled seedbed condition (DAT=0) decreased R by 69% to 3.4 times and increased E by 27%. DT0+S+RF0 plots (best-case scenario) had 2.8 times less R, and 2.6 times less E than CT-S+RF60 plots (worst-case). Based on $1.17ha-mm-1 to pump irrigation water and $18.50ha-1 for DT, a producer in the Coastal Plain region of Georgia would recover cost of DT by saving the first 16ha-mm of water. The DT+S system is a cost-effective management practice for producers in Georgia and the Southeastern U.S. that positively impacts natural resource conservation, producer profit margins, and environmental quality.