Abstract
The frequent occurrence of drought–flood abrupt alternation (DFAA) in Huaibei Plain has shown a great impact on local rice production. Pot experiments were performed in 2016–2018 to investigate the effects of co-occurring drought and flooding stresses on dry weight (DW), grain yield, nitrogen (N), phosphorus (P) and potassium (K) uptake and use efficiencies (NUE, PUE and KUE) in rice. The results showed that DFAA changed the accumulation of biomass and nutrients among different organs in rice. Compared with control, DFAA significantly reduced the grain yield (−29.8%) and root DW (−30.0%), but increased the DW in stem and leaf (10.2% and 9.7%). The root/shoot ratio and morphological size of the root system in DFAA-treated plants was smaller than those of drought alone and flooding alone. Under DFAA stresses, the specific absorption rate of N, P and K increased significantly (47.9%, 31.8% and 32.8%, respectively), while NUE, PUE and KUE decreased significantly (−27.9%, −10.8% and −19.7%, respectively). The decrease of nutrient use efficiencies was mainly due to the redundant growth of branches and leaves, and the key factor limiting grain yield under DFAA conditions was the effective utilization of N. Compared with the earlier drought, the subsequent flooding might have more influence on rice growth, nutrient utilization and yield formation, but the interaction of the two weakened the cumulative effect of drought and flooding. These findings provide a scientific basis for establishing a nutrient and water management system of rice cultivation under transient soil moisture conditions.
Highlights
In recent years, the changing weather patterns have led to extreme changes in the frequency, intensity, spatial extent and duration of rainfall [1]
Among year levels, year × drought levels, year × flooding levels and year × drought levels × flooding levels, those characters apart from the dry weight (DW) of root, stem and leaf, as well as panicle numbers were significant (p < 0.05), which might be due to the increased precipitation, mean air temperature, sunshine hours and mean vapor pressure in July in 2017 and 2018 (Figure 2), leading to the early appearance of panicles
The present study aimed to investigate the interaction of drought and flooding on root growth and nutrient absorption in rice
Summary
The changing weather patterns have led to extreme changes in the frequency, intensity, spatial extent and duration of rainfall [1]. These extreme events occur with increasing frequency and magnitude across the globe [2], which generally negatively affect traditional agriculture in a major way [3]. Some areas experience severe water depletion, whereas others experience excessive rainfall, thereby resulting in flooding [4]. Drought reduced the morphological traits such as leaf area, shoot length and vegetative growth, as well as physiological traits such as the leaf water potential and sap movement in the plants [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
