Impact of alternative irrigation practices on rice quality

Authors: GRAHAM-ACQUAHH, SETH - University Of Arkansas; SIEBENMORGEN, TERRY - University Of Arkansas; Reba, Michele; Massey, Joseph; MAUROMOUSTAKOS, A - University Of Arkansas; Adviento-Borbe, Arlene; JANUARY, ROBIN - University Of Arkansas; BURGOS, R - University Of Arkansas; BALTZ-GRAY, J - University Of Arkansas

Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2019
Publication Date: 7/17/2019
Citation: Graham-Acquahh, S., Siebenmorgen, T.J., Reba, M.L., Massey, J., Mauromoustakos, A., Adviento-Borbe, A.A., January, R., Burgos, R., Baltz-Gray, J. 2019. Impact of alternative irrigation practices on rice quality. Cereal Chemistry. 96:815-823. https://doi.org/10.1002/cche.10182.
DOI: https://doi.org/10.1002/cche.10182

Interpretive Summary: Innovative irrigation strategies in rice production that sustain rice quality are paramount to the longevity of production in the U.S. Mid-South, where 75% of U.S. rice is grown. To ascertain the impact of water-saving irrigation practices on rice quality, three irrigation treatments, namely: continuous flooding with cascade delivery; continuous flooding with multiple-inlet delivery; and alternate wetting and drying (AWD) with multiple-inlet delivery were established on production-sized fields in 2017. Milling yields were not affected by irrigation treatments. The average milled rice and head rice yields across irrigation treatments were 73% and 59% respectively. Rice quality evaluations showed that chalkiness occurred more frequently in AWD fields (5.6%) than in the two continuously-flooded fields (5.1 to 5.2%). Pasting properties such as peak and breakdown viscosities were not affected by irrigation treatments, but setback viscosity, which is often linked with cooked rice texture, was least for the AWD treatment (146 cP) and similar for the continuously-flooded fields (168 to 169 cP). Producers that are implementing these practices, millers that are receiving rice from different irrigation practices, and industry that must consider different characteristics when using rice in products will all benefit from the findings in this study.

Technical Abstract: Current global concerns about water scarcity present a need to investigate more water-efficient rice production methods. Alternate wetting and drying (AWD) is fast emerging as a water-saving irrigation practice, but its effects on rice quality are largely unknown. To ascertain the impact of water-saving irrigation practices on rice quality, three irrigation treatments, namely: continuous flooding with cascade delivery (4 fields); continuous flooding with multiple-inlet delivery (4 fields); and AWD with multiple-inlet delivery (4 fields) were established on 12 production-sized (16.2 ha) fields in 2017. Results of rice quality evaluations showed that irrigation treatment had a significant (P<0.05) effect on chalkiness. Samples harvested from the AWD fields had slightly greater mean chalkiness (5.6%) than samples harvested from the two continuously-flooded fields (5.1 to 5.2%). Milling yields were not affected (P>0.05) by irrigation treatments. The average milled rice and head rice yields across irrigation treatments were 73% and 59% respectively. Regarding pasting properties, while peak and breakdown viscosities were not affected (P>0.05) by the irrigation treatments, setback viscosity (SB), which is often linked with cooked rice texture, was impacted. Among the irrigation treatments, mean SB was least for the AWD treatment (146 cP) while the mean SB for the continuously-flooded fields were similar at 168 to 169 cP. In summary, the use of AWD with multiple-inlet delivery did not impact milling yields of rice relative to the conventional practices of continuous flooding. However, rice harvested from the AWD treatment fields had slightly greater chalkiness and lesser SB.