A sod-based cropping system for irrigation reductions

Abstract

Cotton and peanut grown under irrigation make up over 769,000 ha in the Southeast USA. The consumptive use of water for irrigation has significantly impacted groundwater resources, spring flows and streamflows in many parts of this region, particularly during severe droughts. This situation is further complicated with extreme weather events and climate variability. In this study, we compare yields and water use in a non-irrigated sod-based rotation system (SBR; bahiagrass–bahiagrass–peanut–cotton) to an irrigated conventional rotation system (ICR; peanut–cotton–cotton). Root mass of oat cover crop following peanut or cotton in a SBR and ICR system was also measured. A soil water assessment model (SWAT) was used to simulate irrigation water demands over a 34 yr period (1980–2013) under different soil types to quantify water saving potential of SBR. The average peanut yield in ICR from 2002 to 2013 was 4509 kg ha−1, while that in SBR was 4874 kg ha−1. Likewise the average cotton yield in ICR during the same period was 1237 kg ha−1, while that in SBR was 1339 kg ha−1. Oats had greater root mass in SBR than ICR. Simulation results indicate that crops in SBR consistently had substantially lower irrigation requirements (between 11 and 22 cm yr−1) than those in ICR in dry years. The water-saving potential of SBR varies positively with increasing sand content in soil.

Simulating system‐wide effects of reducing irrigation withdrawals in a disputed river basin

“…Potential water savings from implementing conservation practices such as sod‐based rotation (SBR); (Katsvairo, Wright, Marois, Rich, & Wiatrak, ; Wright et al, ), variable rate irrigation (VRI), and the use of high residue cover crops, conservation tillage, advanced irrigation scheduling, and soil moisture sensing (Perry & Yager, ) were simulated by changing the volume of irrigation withdrawals' effects on stream flow in the Flint River basin and lower Chattahoochee basin by factors informed by research results in and consultations with agricultural irrigation experts working in the basin. These reductions reflect findings that SBR may reduce the need for irrigation by 50% to 75% on peanut and cotton as well as other crops adaptable to the system during drought events (Dourte, Bartel, George, Marois, & Wright, ); low‐pressure drop nozzle retrofits can reduce irrigation water use on pivot or similar systems by up to 22.5%, VRI by an average of 15%, advanced irrigation scheduling by up to 15%, and conservation tillage by up to 15% (Perry & Yager, ). The set of scenarios to modify the agricultural effects on streamflow include (a) Increased Demands: a 25% increase to effects on streamflow due to expansion of irrigation practices and production areas, (b) Current Demands: 2012 agricultural effects on streamflow (Leitman & Kiker, ), (c) Moderate Decrease: a 25% decrease due to widespread adoption of SBR, VRI, and related water‐saving technologies (Dourte et al, ; Perry & Yager, ; Wright et al .…”

“…These reductions reflect findings that SBR may reduce the need for irrigation by 50% to 75% on peanut and cotton as well as other crops adaptable to the system during drought events (Dourte, Bartel, George, Marois, & Wright, ); low‐pressure drop nozzle retrofits can reduce irrigation water use on pivot or similar systems by up to 22.5%, VRI by an average of 15%, advanced irrigation scheduling by up to 15%, and conservation tillage by up to 15% (Perry & Yager, ). The set of scenarios to modify the agricultural effects on streamflow include (a) Increased Demands: a 25% increase to effects on streamflow due to expansion of irrigation practices and production areas, (b) Current Demands: 2012 agricultural effects on streamflow (Leitman & Kiker, ), (c) Moderate Decrease: a 25% decrease due to widespread adoption of SBR, VRI, and related water‐saving technologies (Dourte et al, ; Perry & Yager, ; Wright et al . , ), (d) Large Decrease: a 50% decrease due to an even larger scale adoption of the water saving conservation practices, and (e) Rain‐fed: a 100% decrease (or removal) of demands.…”

Nematicide influence on cotton yield and plant-parasitic nematodes in conventional and sod-based crop rotation

“…Cotton in a conventional rotation may have smaller root systems with more roots located within the fluopyram-treated zone. Sod-based rotation results in cotton with a larger root system that likely developed deep roots (outside of the fluopyram-treated zone) and may explain the nematode populations observed in this study (Dourte et al, 2015). This larger root system may have allowed the plant to compensate for nematode damage.…”

“…Including bahiagrass into the rotation reduces pathogen pressure and builds organic matter, which aids in soil water holding capacity as well as improving other soil properties ( Katsvairo et al, 2006, 2007 ). SBR has been shown to produce high yields with reduced amounts of fertilizer, pesticide, and irrigation ( Norden et al, 1977 ; Wright et al., 2010 ; Dourte et al, 2015 ). Prior research suggests SBR may be beneficial for managing RN during peanut phases, but SBR impacts on RN during cotton phases have not been examined ( Tsigbey et al., 2009 ).…”

Effect of Irrigation Schemes on Forage Yield, Water Use Efficiency, and Nutrients in Artificial Grassland under Arid Conditions

“…Current studies have explored the influence of deficit irrigation on yield and the quality of crops [17][18][19]. Lu et al [20] assessed the influence of drip irrigation by reclaimed water on tomato yield and quality.…”