Response of Grain Quality to Alternate Wetting and Moderate Soil Drying Irrigation in Rice

Abstract

Alternate wetting and moderate soil drying irrigation (WMD) has been widely adopted in rice (Oryza sativa L.) production for saving irrigation water and increasing grain yield. However, limited information is available about the effect of WMD on rice grain quality. The main purpose of this study was to evaluate the characteristics of grain quality in response to WMD. Two rice varieties, Yangdao 6 (YD6, indica) and Hanyou 8 (HY8, japonica), were grown in the field, with two water management treatments, well‐watered (WW) and WMD from 10 d after transplanting to maturity. In comparison with WW, WMD prominently increased grain yield by 7.57 to 9.72%, and improved some grain quality parameters such as milling, appearance, and eating and cooking qualities, including increases in head rice and decreases in chalkiness. The two varieties showed the same tendency. However, WMD had a negative impact on some nutritional quality traits in rice grains, such as reduction in the contents of amino acids and the micronutrient elements Cu, Fe, Mn, Mo, Se, and Zn. The WMD treatment also markedly decreased As content and exhibited no significant effect on Cd content in grains. The results demonstrated that WMD has an overall impact on rice grain quality with both positive and negative effects.

Continuous Flooding or Alternate Wetting and Drying Differently Affect the Accumulation of Health-Promoting Phytochemicals and Minerals in Rice Brown Grain

“…For a few elements, our results are different from those recently reported by Xu and coworkers [18], who compared CF with a moderate soil dry irrigation. In particular, for Mn and Zn their results are essentially consistent with ours, whereas these authors reported that Cu and Fe concentrations decreased in the water-saving regime and in our conditions the Cu concentrations increased and Fe did not show any change (Table 6).…”

“…Different effects of AWD on the concentrations of Cd and As are reported in the literature. The behavior observed in our conditions (increased Cd accumulation and decreased As accumulation in AWD in both years) is in agreement with the results reported by Norton et al [49], but is different, for what concerns Cd, from the results by Xu et al [18], who did not observe any effect of AWD, and, for what concerns As, from the results of Carrijo et al [50], who observed effects on As accumulation only in severe AWD. Most probably these differences depend on the different timing and severity of the imposed AWD condition.…”

“…Although it is well known that the soil water status during rice growth might affect qualitative traits of the grains [16,17], to our best knowledge only a recent paper [18] reported on the possible effects of AWD on grain quality and nutritional value.…”

Effect of controlled soil drying on the grain yield and nutritional quality of rice

“…In terms of grain quality, controlled irrigation improved head rice percentage, chalkiness, and protein content (Xu et al, 2019), although little information is available on the effect of controlled soil drying on grain nutrition and safety. With improvements in living standards, rice breeding has shifted from focusing simply on production to yield and quality simultaneously (Gu et al, 2015).…”

Variation in nutritional quality of pigmented rice varieties under different water regimes

“…In addition to varieties, environments effect by water regimes on the variation of nutritional accumulation in rice have been reported from previous references. The nutrients Cu, Fe, Mn, Mo, Se and Zn in bran and milled rice of non-pigmented rice were decreased by the moderate soil drying when compared with well watered (Xu et al, 2019). Wang et al (2014) reported that alternate wetting and drying (AWD) significantly increased Zn concentration and grain yield.…”