Post-anthesis supplementary irrigation improves grain yield and nutritional quality of drip-irrigated rice (Oryza sativa L.)

Xiangbin Wang; Xinjiang Zhang; Linghui Liu; Xiaowu Liu; Guorui Feng; Juan Wang; Yong-An Yin; Changzhou Wei

doi:10.3389/fpls.2023.1126278

Post-anthesis supplementary irrigation improves grain yield and nutritional quality of drip-irrigated rice (Oryza sativa L.)

Front Plant Sci. 2023 Apr 5:14:1126278. doi: 10.3389/fpls.2023.1126278. eCollection 2023.

Authors

Xiangbin Wang¹, Xinjiang Zhang¹, Linghui Liu¹, Xiaowu Liu², Guorui Feng¹, Juan Wang¹, Yong-An Yin², Changzhou Wei¹

Affiliations

¹ College of Agriculture, Shihezi University, Shihezi, Xinjiang, China.
² Technical Center of Xinjiang Tianye (Group) Co., Ltd., Shihezi, Xinjiang, China.

Abstract

Introduction: Approximately 50% of irrigation water is saved during drip-irrigation of rice, which has tremendous potential for water-saving agriculture, particularly in areas where water resources are scarce. However, the grain yield and quality of drip-irrigated rice are adversely affected.

Methods: In this study, we investigated the effects of different irrigation strategies on the grain yield and quality of drip-irrigated rice using field experiments. Four irrigation treatments were studied: whole growing season flooding (FI), whole growing season normal drip irrigation (DI, soil relative moisture (RSM) was maintained in the range of 90-100%), pre-anthesis drip irrigation and post-anthesis water stress (SAF, the RSM was maintained in the range of 80-90% after anthesis), pre-anthesis drip irrigation, and post-anthesis flooding (FAF).

Results: The results showed that grain yield, harvest index, seed setting rate and 1000 grain weight in DI and SAF were significantly lower than in FI and FAF. These parameters were not significantly different between FI and FAF but were significantly greater in DI than in SAF. Compared with FI and FAF, the source capacity, source activity time, and sink activity of DI and SAF decreased, and the sink-source difference increased. The sink-source difference had a significant negative correlation with rice yield and 1000 grain weight. The activities of ADP-glucose pyrophosphorylase, starch branching enzyme, and amylopectin content in grains in the middle panicles of FAF were significantly higher than those of DI and SAF. SAF resulted in increased amylose/amylopectin ratio and total protein content in grains but decreased proportion of glutenin in total protein. Irrigation after anthesis of drip-irrigated rice narrowed the difference between sink sources in rice plants, increased the grain yield and harvest index by 29.2% and 11%, respectively, compared to DI, increased water productivity by 19% compared to FI, and improved the grain quality of drip-irrigated rice.

Discussion: This study highlights that post-anthesis sufficient irrigation of drip-irrigated rice plays a positive role in maintaining the source-sink balance. This study serves as a foundation for the development of more effective rice farming methods that conserve water, while increasing the grain yield and quality of drip-irrigated rice.

Keywords: protein components; source-sink relationship; starch synthesis; water productivity; water-saving cultivation.

Grants and funding

This research was funded by National Natural Science Foundation of China (Project Number: 31860587) entitled: “Study on Enhanced Ammonium Nutrition Alleviate Drip-irrigated Rice Chlorosis in Calcareous Soil”, National Natural Science Foundation of China (Project Number: 32060721) entitled: “Study on The Relationship between Water Dynamics and Spikelet Degeneration of Rice in The Drip-irrigation Field”.