Furrow diking in conservation tillage

Crop production in the Southeastern U.S. can be limited by water; thus, supplemental irrigation is needed to sustain profitable crop production. Increased water capture would efficiently improve water use and reduce supplemental irrigation amounts/costs, thus improving producer’s profit margin. We quantified infiltration (INF), runoff (R), and sediment (E) losses from furrow diked (+DT) and non-furrow diked ( DT) tilled conventional (CT) and strip tillage (ST) systems. In 2008, a field study (Tifton loamy sand, Typic Kandiudult) was established with DT, ST, and CT systems. In 2009, a field study (Faceville loamy sand, Typic Kandiudult) was established with DT and ST systems. Treatments (6) included: CT DT, CT + DT, ST1 (1-year old) DT, ST1 + DT, ST10 (10-year old) DT, and ST10 + DT. Simulated rainfall (50 mm h 1 for 1 h) was applied to each 2-m 3-m plots (n = 3). Runoff and E were measured from each 6-m plot. ST1 + DT plots had 80–88% less R than ST1 DT plots. Any disturbance associated with DT in ST1 systems did not negatively impact E values. For both soils, CT DT plots represented the worst-case scenario in terms of measured R and E; ST + DT plots represented the best-case scenario. Trends for R, E, and estimated plant available water (PAW) values decreased in order of CT DT, CT + DT, ST1 DT, ST1 + DT, ST10 DT, and ST10 + DT treatments. From a hydrology standpoint, ST1 DT plots behaved more similarly to CT plots than to other ST plots; from a sediment standpoint, ST1 DT plots behaved more similarly to other ST plots than to CT plots. DT had no effect on ST10 plots. CT DT and ST10 + DT plots resulted in 5.9 (worst-case) and 8.1 (best-case) days of water for crop use, a difference of 2.2 days of water for crop use or 37%. Compared to the CT DT treatment, an agricultural field managed to CT + DT, ST1 DT, ST1 + DT, ST10 DT, and ST10 + DT would save a producer farming the CT DT field $5.30, $9.42, $13.55, $14.14, and $14.14 ha , respectively, to pump the amount ofwater lost to R and not saved as INF back onto the field. The most water/cost savings occurred for CT and ST1 plots as a result of DT. Savings for CT + DT, ST1 DT, and ST1 + DT treatments represent 27%, 47%, and 68% of the cost of DT ($20 ha ) and 37%, 67%, and 96% of the savings a producer would have if managing the field to ST for 10 years without DT (ST10 DT) in a single 50-mm rainfall event. For row-crop producers in the Southeastern U.S. with runoff producing rainfall events during the crop growing season, DT is a management practice that is cost-effective from a natural resource and financial standpoint for those producers that continue to use CT systems and especially those that have recently adopted ST systems into their farming operations. Published by Elsevier B.V.