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ARS Home » Southeast Area » Jonesboro, Arkansas » Delta Water Management Research » Research » Publications at this Location » Publication #331627
Title: Alternate wetting and drying in high yielding direct-seeded rice systems accomplishes multiple environmental and agronomic objectives

Author
item LAHUE, GABRIEL - University Of California
item CHANEY, RUFUS - US Department Of Agriculture (USDA)
item Adviento-Borbe, Arlene
item LINQUIST, BRUCE - University Of California

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2016
Publication Date: 6/1/2016
Publication URL: http://handle.nal.usda.gov/10113/63212
Citation: Lahue, G., Chaney, R., Adviento-Borbe, A.A., Linquist, B. 2016. Alternate wetting and drying in high yielding direct-seeded rice systems accomplishes multiple environmental and agronomic objectives. Agriculture, Ecosystems and Environment. 229:30-39.

Interpretive Summary: Rice production needs to increase yield to meet world's growing population. However, intensification of irrigated flooded rice system is responsible for increased greenhouse gas (GHG) emissions and demand for water resource. Alternate wetting and drying (AWD )practice of rice field is a water-saving technology that reduces methane emissions and water use but this innovative irrigation management may reduce rice production due to potential water stress. This study highlights the efficacy of AWD practice to decrease GHG emissions as well as heavy metal in the grain with no reduction of yield. The AWD practice is an innovative water management strategy that rice growers can implement to solve the problem of water scarcity in some regions of the US. However, despite the many environmental benefits of AWD in rice fields, there are significant challenges to consider in the adoption of AWD across the US and these are the risk of yield loss with improper water and fertilizer N management and limited information on AWD management at large scales.

Technical Abstract: Rice (Oryza sativa L.) cultivation is critically important for global food security, yet it also represents a significant fraction of agricultural greenhouse gas (GHG) emissions and water resource use. Alternate wetting and drying (AWD) of rice fields has been shown to reduce both methane (CH4) emissions and water use, but its effect on grain yield is variable. In this three-year study we measured CH4 and nitrous oxide (N2O) emissions, rice grain total arsenic (As) concentrations, yield response to N rate, and grain yield from two AWD treatments (drill-seeded and water-seeded) and a conventionally managed water-seeded treatment (control). Grain yields (average = 10 Mg/ha) were similar or higher in the AWD treatments compared to the control and required similar or lower N rates to achieve these yields. Furthermore, AWD reduced growing season CH4 emissions by 60–87% while maintaining low annual N2O emissions (average = 0.38 kg N2O–N ha1); N2O emissions accounted for <15% of the annual global warming potential (GWP) in all treatments. Fallow season emissions did not vary by treatment and accounted for 22–53% of annual CH4 emissions and approximately one third of annual GWP on average. The AWD treatments reduced annual GWP by 57–74% and growing season yield-scaled GWP by 59–88%. Milled grain total As, which averaged 0.114 mg kg1 in the control, was reduced by 59–65% in the AWD treatments. These results show that AWD has the potential to mitigate GHG emissions associated with rice cultivation and reduce rice grain total As concentrations without sacrificing grain yield or requiring higher N inputs; however future research needs to focus on adapting AWD to field scales if adoption of this technology is to be realized.