Optimum Planting Density and Nitrogen Application Rate for Maximizing Rice Yield in the Nile Delta

2003 ◽  
Vol 72 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Teruhisa NAMBA
Keyword(s):  
Nile Delta ◽  
Rice Yield ◽  
Application Rate ◽  
Planting Density ◽  
Nitrogen Application ◽  
Nitrogen Application Rate

scholarly journals Response of Rice Harvest Index to Different Water and Nitrogen Management Modes in the Black Soil Region of Northeast China

Agriculture ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 115
Author(s):  
Sicheng Du ◽  
Zhongxue Zhang ◽  
Tiecheng Li ◽  
Zhongbo Wang ◽  
Xin Zhou ◽  
...  
Keyword(s):  
Northeast China ◽  
Agricultural Development ◽  
Rice Yield ◽  
Black Soil ◽  
Application Rate ◽  
Nitrogen Management ◽  
Nitrogen Application ◽  
Black Soil Region ◽  
Management Modes ◽  
Nitrogen Application Rate

Understanding the methods leading to rice yield increase is vital for sustainable agricultural development. Improving the harvest index (HI) is an important way to increase rice yield. To explore the effects of different water and nitrogen management modes on the rice HI in the black soil region of Northeast China, a field experiment was conducted in 2019 (Y1) and 2020 (Y2). Two irrigation methods, conventional flooding irrigation (FI) and controlled irrigation (CI), were established in the experiment, and four nitrogen application levels (0 kg/ha, 85 kg/ha, 110 kg/ha, and 135 kg/ha) were set during the entire growth period, named N0, N1, N2, and N3. The dry matter weight and the rice yield at the maturity stage were determined, and the HI was then calculated. The results showed that different irrigation modes and nitrogen application levels had significant effects on the rice HI. Under different irrigation modes with the same nitrogen application level during the two years, the comparison regular of HI was consistent. In Y1 and Y2, the HI of FN0 was 3.36% and 5.02% higher than that of CN0 (p < 0.05), and the HI of CN1 was 0.31% and 2.43% higher than that of FN1 (p > 0.05). The HI under CI was significantly higher than that under FI under N2 and N3 (p < 0.05), the HI of CN2 was 4.21% and 4.97% higher than that of FN2, and the HI of FN3 was 13.12% and 20.34% higher than that of CN3. In addition, during the two-year experiment, the HI first increased and then decreased with an increase in the nitrogen application rate under FI and CI. Under the FI treatments, the HI of N1 was the highest, and that of N2 was the highest under the CI treatments. A variance analysis showed that the irrigation pattern and nitrogen application level had significant interactions on the rice HI (p < 0.01), and the appropriate water and N management mode could increase rice the HI by 26.89%. The experimental results showed that the HI of the 110 kg/ha nitrogen application rate under CI was the highest, reaching 0.574 and 0.572, respectively, in two years. This study provides a data reference and theoretical support for realizing water savings, nitrogen reduction, and sustainable agricultural development in the black soil region of Northeast China.

Cotton physiological and agronomic response to nitrogen application rate

2021 ◽  
Vol 270 ◽  
pp. 108194
Author(s):  
John Snider ◽  
Glendon Harris ◽  
Phillip Roberts ◽  
Calvin Meeks ◽  
Daryl Chastain ◽  
...  
Keyword(s):  
Application Rate ◽  
Nitrogen Application ◽  
Nitrogen Application Rate

scholarly journals Effects of nitrogen application rate on the photosynthetic pigment, leaf fluorescence characteristics, and yield of indica hybrid rice and their interrelations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinfeng Peng ◽  
Yuehua Feng ◽  
Xiaoke Wang ◽  
Jie Li ◽  
Guiling Xu ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Hybrid Rice ◽  
Photosynthetic Pigment ◽  
Application Rate ◽  
Maturity Stage ◽  
Nitrogen Application ◽  
Fluorescence Characteristics ◽  
Heading Stage ◽  
Indica Hybrid Rice ◽  
Nitrogen Application Rate

AbstractA field experiment employing the rice cultivars Qyou6 and Yixiangyou2115 as materials and different nitrogen application rates was conducted in Huangping County, Guizhou Province in 2019 to determine the effects of nitrogen application rate on photosynthetic pigments, leaf fluorescence characteristics, yield, and their interrelations in indica hybrid rice. The results showed that photosynthetic pigment contents generally increased with increasing nitrogen application rate. As the nitrogen rate increased, the maximal quantum yield of PSII (Fv/Fm), actual quantum yield of PSII (ΦPSII), and relative electron transfer rate at PSII (ETR) first decreased and then increased at the booting stage; Fv/Fm and ΦPSII decreased while ETR first increased and then decreased at the heading stage; nevertheless, Fv/Fm and ΦPSII first decreased and then increased but ETR was just the opposite at the maturity stage. Non-photochemical quenching coefficient (qN) and quantum yield of regulatory energy dissipation at PSII (Y(NPQ)) first increased and then decreased whereas quantum yield of non-regulatory energy dissipation at PSII (Y(NO)) first decreased and then increased at the booting, heading, and maturity stages with increasing nitrogen application rate. Photochemical quenching coefficient (qP) showed an increasing trend as the nitrogen rate increased in the range of 150–300 kg/ha at the heading and maturity stages. Photosynthetic pigments, leaf fluorescence characteristics, and yield and its components were significantly correlated. First, chlorophylls a and b were significantly negatively correlated with Fv/Fm while significantly positively correlated with qP at the heading stage. Secondly, Carotenoids were significantly positively correlated with the effective panicle number (EPN) at the booting stage while significantly negatively correlated with the spikelets per panicle (SPP) at the heading stage. Chlorophyll a and carotenoids were significantly positively correlated with EPN but significantly negatively correlated with spikelet filling (SF) at the maturity stage. In addition, qP was significantly negatively correlated with EPN at the booting stage. At the heading stage, Fv/Fm and Y(NO) were significantly negatively correlated with EPN and SPP, respectively, and Fv/Fm and ΦPSII were significantly positively related to SF. Moreover, qP was extremely significantly positively related to EPN whereas Fv/Fm was extremely significantly negatively correlated with grain yield at the maturity stage. Appropriate nitrogen application rates can enhance photosynthetic pigment contents, improve the photochemical efficiency and proportion of the open part of the reaction center of PSII, and promote the quantum efficiency and self-protection ability of PSII, thereby increasing photosynthetic efficiency and yield. Under the conditions adopted in this experiment, a parabolic relationship was observed between the nitrogen application rate and grain yield. The regression analysis results showed that the best nitrogen application rate of indica hybrid rice is 168.16 kg ha−1 and the highest yield is 11,804.87 kg ha−1.

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