scholarly journals Recommended nitrogen rates and the verification of effects based on leaf SPAD readings of rice

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12107
Author(s):  
Wenfeng Hou ◽  
Juan Shen ◽  
Weitao Xu ◽  
Muhammad Rizwan Khan ◽  
Yin Wang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Production Systems ◽  
N Fertilization ◽  
N Use Efficiency ◽  
Plant Nitrogen ◽  
Use Efficiency ◽  
N Rates ◽  
Spad Readings ◽  
N Use

Modern rice production systems need a reliable, easy-to-use, efficient, and environmentally-friendly method to determine plant nitrogen (N) status , predict grain yield, and optimize N management. We conducted field experiments to determine the influence of different N rates on Soil Plant Analysis Development (SPAD) readings of rice leaves. We also performed field validations to evaluate the grain yield and N use efficiency under recommended N rates. Our results showed that leaf SPAD readings increased as N rates increased. We applied the recommended N based on the relationships between the N rates and leaf SPAD readings at the tillering and booting stages. The recommended N decreased N rates and improved N use efficiency without sacrificing grain yield. When compared to farmer practices (FP), the recommended N rates of optimization (OPT) decreased by 5.8% and 10.0%, respectively. In comparison with FP, the N agronomic efficiency of OPT increased by 5.8 and 10.0% while the partial factor productivity of N increased by 6.0 and 14.2%, respectively. The SPAD meter may be a reliable tool to analyze the N in rice, estimate real-time N fertilization, and improve N use efficiency.

scholarly journals Nitrogen fertilization impact on agronomic traits of maize hybrids released at different decades

2001 ◽  
Vol 36 (5) ◽  
pp. 757-764 ◽  
Author(s):  
Luís Sangoi ◽  
Márcio Ender ◽  
Altamir Frederico Guidolin ◽  
Milton Luiz de Almeida ◽  
Valmor Antônio Konflanz
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Genetic Selection ◽  
N Use Efficiency ◽  
Yield Potential ◽  
Breeding Cycle ◽  
Maize Hybrids ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

Genetic selection of maize hybrids is often conducted using high N rates during the breeding cycle. This procedure may either lead to the release of genotypes that present nitrogen luxury consumption or require a stronger N input to accomplish their yield potential. This work was carried out to evaluate the effects of N rates on grain yield and N use efficiency of hybrids cultivated in different decades in Southern Brazil. The trial was performed in Lages, Santa Catarina State. A split plot design was used. Hybrids Ag 12, Ag 28, Ag 303 and Ag 9012, released during the 60's, 70's, 80's and 90's, respectively, were evaluated in the main plots. Nitrogen rates equivalent to 0, 50, 100 and 200 kg ha-1 were side-dressed in the split-plots when each hybrid had six fully expanded leaves. Modern-day hybrid Ag 9012 had higher grain yield than hybrids of earlier eras, regardless of N rates. Under high doses of N, the older hybrids Ag 12 and Ag 28 took up more N and presented higher values of shoot dry matter at flowering than Ag 9012. Nonetheless, they set less grains per ear which contributed to decrease their grain yield and N use efficiency.

Effect of nitrogen rate and fertilizer nitrogen source on physiology, yield, grain quality, and nitrogen use efficiency in corn

2016 ◽  
Vol 96 (3) ◽  
pp. 392-403 ◽  
Author(s):  
Dilip K. Biswas ◽  
Bao-Luo Ma
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
N Uptake ◽  
N Use Efficiency ◽  
Canopy Reflectance ◽  
Calcium Ammonium Nitrate ◽  
N Source ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

A two-year (2010–2011) field experiment was undertaken to examine the effect of nitrogen (N) rate (0, 100, 150, and 200 kg N ha−1) and N source (urea, calcium ammonium nitrate; ammonium sulphate) on canopy reflectance, chlorophyll pigments, photosynthesis, yield, grain quality, and N-use efficiency in corn. However, the physiological observations were made only in 2011. We found that stover biomass was unaffected by higher N rate beyond 150 kg N ha−1 in both years. Higher N rates did not provide a yield advantage as compared to 150 kg N ha−1 in 2010, but the highest grain yield was produced with 200 kg N ha−1 in 2011. The higher grain yield by N application was attributed to a greater kernel size in both years. Corn stover [N] was found to increase with increasing N rates in both years. Kernel [N] only responded to the high N rate in 2010. There was no change in the kernel density as affected by N rate in both years. An increased N addition resulted in a decrease in both N-uptake efficiency and agronomic-N use efficiency in both years. There was an inconsistent effect of N source on yield and N use efficiency indices in the corn over two years.

scholarly journals Liming Optimizes Nitrogen Fertilization in a Maize-Upland Rice Rotation under No-Till Conditions

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2005
Author(s):  
Carlos Alexandre Costa Crusciol ◽  
Letusa Momesso ◽  
Murilo de Campos ◽  
João William Bossolani ◽  
José Roberto Portugal ◽  
...  
Keyword(s):  
Crop Yields ◽  
Upland Rice ◽  
Chemical Properties ◽  
N Fertilization ◽  
N Use Efficiency ◽  
Agricultural System ◽  
No Till ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

Liming and N fertilization are common practices for optimizing crop yields in tropical agriculture, but the adequate N rate to ensure crop development, enhance yields and N use efficiency, and improve soil chemical properties has not been established for grass rotation. We assessed the optimal N fertilizer rate for combination with liming in an agricultural system composed of two grasses (maize and rice) in rotation under no-till (NT) conditions. Four N rates (0, 50, 100, and 150 kg N·ha−1) were tested under two liming conditions. Maize (11 Mg·ha−1) and rice (5 Mg·ha−1) yields were highest with lime and 150 kg N·ha−1 applications. At 18 months after liming, lime application increased soil pH. In addition, combining liming with N fertilization further increased SOM content at all N rates. Lime increased available P, exchangeable Ca2+ and Mg2+, and BS at N rates of 0, 50, and 100 kg N·ha−1. Overall, combining liming and N fertilization is beneficial for grass crops under NT conditions, as evidenced by enhanced maize and rice N use efficiency and yields. N fertilization rates of 100 and 150 kg N·ha−1 under lime amendment provided the best improvements in crop yields in this cropping system.

GRAIN YIELD AND NITROGEN UTILIZATION IN RESPONSE TO REDUCING NITROGEN RATE IN HYBRID RICE TRANSPLANTED AS SINGLE SEEDLINGS

2018 ◽  
Vol 55 (04) ◽  
pp. 637-648 ◽  
Author(s):  
MIN HUANG ◽  
SHUANGLÜ SHAN ◽  
XIAOBING XIE ◽  
XUEFENG ZHOU ◽  
YINGBIN ZOU ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Loss ◽  
Hybrid Rice ◽  
N Use Efficiency ◽  
Yield Reduction ◽  
Yield Attributes ◽  
N Utilization ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

SUMMARYTransplanting single seedlings rather than seedlings in clumps has been increasingly attractive in hybrid rice production in China due to reduced seed requirements and higher grain yield. This study was conducted to determine grain yield and nitrogen (N) utilization in response to reductions in the N rate in hybrid rice under single-seedling transplanting. Field experiments were done in 2015 and 2016 on a moderate to high fertility soil at the Experimental Farm of Hunan Agricultural University, China. The hybrid rice cultivar Liangyoupeijiu (LYPJ) was used in 2015, and two hybrid cultivars LYPJ and Xiangliangyou 900 were used the next year. In each year, the rice plants transplanted with a single seedling per hill were grown with three N rates, including the usual N rate (150 kg ha–1) and two reduced N rates (120 and 90 kg ha–1). Grain yield, yield attributes, and N uptake and use efficiency were determined for each N rate. Significant reduction in grain yield was observed in only one of three cultivar-year combinations when N rate was reduced by 20% (from 150 to 120 kg ha–1), and the magnitude of yield reduction was only 4%. Although significant reduction in grain yield was observed in two of the three cultivar-year combinations when N rate reduced by 40% (to 90 kg ha–1), the highest yield reduction was only 7%. Yield attributes were generally changed slightly when N rate was reduced by 20%, while compensation among yield attributes and N utilization characteristics could explain why a 40% reduction in N rate did not result in substantial yield loss. Partial factor productivity of applied N (PFPN) was increased by 21–24% and 56–63% with 20% and 40% reductions in the N rate, respectively. The higher PFPN with a reduced N rate was attributed to higher recovery efficiency of applied N (REN) or to both higher REN and internal N use efficiency. Our study suggests that reducing N rate does not necessarily result in yield loss due to compensation among yield components and increased N use efficiency in hybrid rice transplanted as single seedlings under moderate to high soil fertility conditions.

scholarly journals Biochar Integration with Legume Crops in Summer Gape Synergizes Nitrogen Use Efficiency and Enhance Maize Yield

Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 58 ◽  
Author(s):  
Fazal Jalal ◽  
Muhammad Arif ◽  
Kashif Akhtar ◽  
Aziz Khan ◽  
Misbah Naz ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
N Use Efficiency ◽  
Mineral Fertilizers ◽  
Cropping Pattern ◽  
Above Ground Biomass ◽  
Mineral N ◽  
Ground Biomass ◽  
Use Efficiency ◽  
N Use

Besides carbon (C) sequestration, biochar (BC) is recently believed to deliver multiple eco-friendly benefits to the soil for enhancing crop productivity. Use of mineral fertilizers coupled with BC been suggested a promising sustainable strategy for increasing crops yield. However, imperative study is needed to investigate (1) BC integration with multiple legumes crop adjusted in summer gape for pooling more organic carbon and nitrogen, and (2) subsequently looking into its synergism with mineral N in the following crop. Therefore, two years’ field experiments were conducted on maize under cereal based cropping pattern with the adjustment of legumes (i.e., mungbean, cowpea, and Sesbania) with a fallow in summer. In legumes, treatments consist of (0 and 50 t ha−1) BC application. However, N rates of 0, 90, 120, 150 kg ha−1 were added to the subsequent maize crop. Preceding legumes plots with the use of 50 t ha−1 biochar enhanced maize grain yield, above ground biomass, stover N, grain N, soil C, and N content after maize harvest and N use efficiency as compared to non-legumes with BC and legumes without BC plots. N application increased grain yield, above-ground biomass, stover N, grain N, and soil N but reduced N use efficiency with higher rates. Conclusively, the integration of biochar and legumes is a promising option for increasing the entire farm production of cereal-based cropping systems. This increment in yield was associated with supplying a viable input of N and C to soil and increased yields from this supplementary ‘summer gap’ crop.

INFLUENCE OF THE SYSTEM OF RICE INTENSIFICATION ON RICE YIELD AND NITROGEN AND WATER USE EFFICIENCY WITH DIFFERENT N APPLICATION RATES

2009 ◽  
Vol 45 (3) ◽  
pp. 275-286 ◽  
Author(s):  
LIMEI ZHAO ◽  
LIANGHUAN WU ◽  
YONGSHAN LI ◽  
XINGHUA LU ◽  
DEFENG ZHU ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
N Use Efficiency ◽  
System Of Rice Intensification ◽  
N Application ◽  
Application Rates ◽  
Rice Intensification ◽  
Use Efficiency ◽  
N Rates ◽  
N Use

SUMMARYField experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.

Integrated nutrient, water and other agronomic options to enhance rice grain yield and N use efficiency in double-season rice crop

2013 ◽  
Vol 148 ◽  
pp. 15-23 ◽  
Author(s):  
Jianquan Qin ◽  
S.M. Impa ◽  
Qiyuan Tang ◽  
Shenghai Yang ◽  
Jian Yang ◽  
...  
Keyword(s):  
Grain Yield ◽  
N Use Efficiency ◽  
Rice Crop ◽  
Rice Grain ◽  
Use Efficiency ◽  
N Use

scholarly journals Growth, Critical N Concentration and Crop N Demand in Butterhead and Crisphead Lettuce Grown under Mediterranean Conditions

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 681 ◽  
Author(s):  
Conversa ◽  
Elia
Keyword(s):  
Field Experiments ◽  
Environmental Issues ◽  
Dry Weight ◽  
Crop Productivity ◽  
N Fertilization ◽  
Use Efficiency ◽  
Butterhead Lettuce ◽  
N Demand ◽  
N Use ◽  
Critical N Concentration

Excessive nitrogen (N) fertilizers are applied in lettuce causing both environmental issues and N crop luxury consumption. In order to improve the N use efficiency (NUE) by defining optimal crop growth and N requirements of butterhead and crisphead lettuce, two field experiments were conducted using 0, 50, and 100 kg ha−1 of N fertilizer to study (i) the growth and productivity, (ii) the NUE, (iii) the critical N dilution curve, and (iv) the N demand. Nitrogen supply enhanced dry weight (DW) accumulation in the butterhead (from 295 to 410 g m−2), but not in the crisphead type (251 g m−2). The NUE indices underlined the poor ability of the crisphead type in absorbing soil N and also in the utilization of the absorbed N for producing DW. The critical N dilution curves %Nc = 3.96 DW−0.205 and %Nc = 3.65 DW−0.115 were determined for crisphead and butterhead lettuce, respectively. Based on these type-specific %Nc curves, the estimated N demand was 125 kg ha−1 in the butterhead and 80 kg ha−1 in the crisphead lettuce for producing 4.3 and 2.5 Mg ha−1 of DW, respectively, under Mediterranean climate. Neither N fertilization nor genotype affected crop productivity.

Nitrogen uptake and N-use efficiency of Mediterranean cotton under varied deficit irrigation and N fertilization

2016 ◽  
Vol 73 ◽  
pp. 144-151 ◽  
Author(s):  
S. Stamatiadis ◽  
C. Tsadilas ◽  
V. Samaras ◽  
J.S. Schepers ◽  
K. Eskridge
Keyword(s):  
Nitrogen Uptake ◽  
Deficit Irrigation ◽  
N Fertilization ◽  
N Use Efficiency ◽  
Use Efficiency ◽  
N Use

Physiological and biochemical indicators for assessing nitrogen-use efficiency in rice (Oryza sativa) genotypes under dry direct seeding

2016 ◽  
Vol 67 (11) ◽  
pp. 1158 ◽  
Author(s):  
Rupinder Kaur ◽  
Seema Bedi ◽  
Gulshan Mahajan ◽  
Gurpreet Kaur ◽  
Bhagirath Singh Chauhan
Keyword(s):  
Grain Yield ◽  
Block Design ◽  
Soluble Sugars ◽  
Biochemical Traits ◽  
High Productivity ◽  
Use Efficiency ◽  
Rice Genotypes ◽  
N Rates ◽  
Physiological And Biochemical ◽  
N Use

To achieve high productivity of labour and water in rice cropping, farmers in South Asia have recently shown more interest in dry direct-seeded rice (DSR). An understanding of physiological and biochemical traits associated with high grain yield and efficiency of nitrogen (N) use is important to the development of genotypes for DSR. We investigated this issue with rice genotypes adapted to DSR in response to N rates. A 2-year study was conducted in a factorial randomised complete block design with eight genotypes and two N rates (75 and 150 kg N ha–1). Almost all of the physiological and biochemical traits studied (e.g. plant height, chlorophyll content, panicle weight, soluble sugars, starch) in DSR improved with increasing N from 75 to 150 kg ha–1, resulting in a 6% increase in yield at 150 kg N ha–1 relative to 75 kg N ha–1. Partial factor productivity of N was highest for the genotype IET-23455 (72.4 kg kg–1) and lowest for the genotype AAUDR (37.4 kg kg–1). Our results suggest that genotypes such as IET-23455 can maintain grain yield at low N rates as N-efficient genotypes. The greater biochemical activity (nitrate reductase and glutamine synthetase, sugar, protein and proline) and higher photosynthetic N-use efficiency at low N rates could be used in selection for N-efficient rice genotypes for DSR.

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