Yield and potassium uptake of rice as affected by potassium rate in the middle reaches of the Yangtze River, China

Abstract

Yield and potassium uptake of rice as affected by potassium rate in the middle reaches of the Yangtze River, China Abstract Potassium is an essential macroelement for rice (Oryza sativa L.), but K deficiency in paddy ecosystems has increased widely and limited sustainable rice production in China. Two-year field trials were conducted with five K levels (0, 60, 120, 180, and 240 kg K 2 O ha -1 , designated as K0, K60, K120, K180, and K240) in Qichun county, Hubei Province, to investigate grain yield, K uptake characteristics, and K use efficiencies of rice. The results showed that application of K increased rice yield by 9.8-29.3%, compared to K0. No significant differences were observed in rice yield among the K120, K180, and K240 treatments. The K uptake in aboveground biomass increased linearly with the K rate, while K harvest index decreased. As K uptake increased, rice yield increased linearly at first and then stabilized, showing the phenomenon of luxury consumption of K. The growth period for fast K uptake in different rice varieties and K levels was 29-67 d after transplanting, and sufficient nutrient supply is needed to ensure the increase of rice yield and growth during this period. Internal use efficiency (IUE), agronomic efficiency (AE), and physiological efficiency (PE) declined as the application rate of K increased. These results indicated that absorption and utilization of K in rice were affected by the K supply rates, and that luxury consumption occurred when K application was excessive. The luxury consumption of K by rice was mainly stored in straw.Abbreviations: AE, agronomic efficiency; F1, Fengliangyouxiang no. 1; H3, Hua'an no. 3; IUE, internal use efficiency; KHI, K harvest index; L6326, Liangyou 6326; PE, physiological efficiency; RIE, reciprocal internal efficiency; t 1 , the beginning peak period; t 2 , peak period; t 3 , the end peak period; v m , the maximum uptake rate of potassium; Y6, Yangliangyou no. 6; Δt, the time of potassium rapid accumulation lasted.

Determination of critical Y‐leaf potassium concentrations in pure‐line and hybrid rice

“…The maximum yield increases from K fertilization measured in the five K‐responsive, pure‐line rice trials (Table 3) are comparable to the yield responses documented in the published literature (Fryer et al., 2019; Slaton et al., 2009; Slaton et al., 2010; Ye et al., 2020). Slaton et al.…”

“…The greater biomass and grain yield produced by hybrid cultivars compared with pure‐line cultivars (Mahajan & Chauhan, 2016; Slaton et al., 2010) would seem to increase the demand for and responsiveness to fertilizer K when grown on K‐deficient soils as suggested by Doberman and Fairhurst (2000). Hybrids have been shown to respond positively to K fertilization (Ye et al., 2020) and rice genotypes may respond differently to K fertilization (Yang et al., 2003). However, we could not find any literature suggesting consistent differences in response to K between pure‐line and hybrid cultivars.…”

Dynamics of Growth and Nitrogen Capture in Winter Oilseed Rape Hybrid and Line Cultivars under Contrasting N Supply

“…The logistic equation is one of the most frequently used nonlinear functions that have been developed to model important aspects of crop growth, including crop and kernel development, biomass accumulation [33][34][35]. It performed reasonably well in interpreting the dynamics of biomass and nutrient accumulation in major crops including rice [42,43], cotton [34,36], maize [44] and winter wheat [25]. In the present study, the simulated values of the aboveground biomass and N accumulation in winter oilseed rape cultivars were in good agreement with the measured values with R 2 of 0.919-0.999, RMSE of 1.0-14.1% and EF of 0.911-0.999, which could suggest reasonable accuracy in model simulation according to previous studies [27,45].…”

Optimized potassium application rate increases foxtail millet grain yield by improving photosynthetic carbohydrate metabolism

“…Potassium application could effectively increase the K contents of each organ, and higher K applications have yielded higher proportions of stem distribution. However, despite the absorption of stem potassium, no significant changes in grain K contents have been observed ( Ye et al., 2020 ). Potassium uptake by cereal crops mainly occurs before the flowering stage, and the K required during grain development is mainly obtained via transport from the vegetative organs ( Zhang et al., 2016 ).…”

“…Cereal crops have high K demands, and the amount of K required for 100 kg of grain is 2-3 kg (Xie et al, 2009). Ye et al (2020) used the linear plus platform model to determine that the suitable potassium application rate for high rice quality and yield was kg•hm −2 of K 2 O. Sun et al (2014) suggested that 133.5 kg•hm −2 of K 2 O was suitable for millet in central Shanxi.…”