Abstract:

Direct seeding and brackish water irrigation represent an important way to alleviate the labor shortage and progressive water scarcity for rice production in the Yellow River Delta. However,the exact impact of these methods on the growth,yield and quality of rice is still unclear. The present study used a split-plot experimental design with irrigation as the main plot and cultivation methods as the subplot from 2019 to 2020. The experiment had two levels each of irrigation(F.Freshwater irrigation;B.Brackish water irrigation)and three seeding methods(D.Dry direct seeding;W.Wet direct seeding;T.Transplanting). The study identified wet direct seeding was conducive to enhance rice height,while dry direct seeding was beneficial for promoting leaf area per rice and dry matter per rice. And,the above agricultural traits were significantly reduced by brackish water irrigation. Brackish water irrigation decreased rice yield by reducing yield components. In 2019 and 2020,the rice yield of transplanting by freshwater irrigation was 749.93,713.58 kg/ha higher than dry direct seeding,although the yield was also higher than wet direct seeding,the difference was not significant. Furthermore,the yield of wet direct seeding was higher than transplanting under brackish water irrigation condition,the yield difference was also not significant. The processing quality,appearance quality and protein content by wet direct seeding were significantly higher than transplanting. And brackish water irrigation contributed to the reduction of processing quality,appearance quality and taste value. Brackish water irrigation combined with direct seeding significantly reduced the yield and quality of rice,lowering the taste value despite the elevated protein and amylose content. Thus,the selection and breeding of salt-tolerant rice varieties suitable for wet direct seeding should be enhanced in the future research.

Key words: Rice, Seeding method, Brackish water irrigation, Yield, Quality, Yellow river delta