scholarly journals In-Season Diagnosis of Rice Nitrogen Status Using Proximal Fluorescence Canopy Sensor at Different Growth Stages

2019 ◽  
Vol 11 (16) ◽  
pp. 1847 ◽  
Author(s):  
Shanyu Huang ◽  
Yuxin Miao ◽  
Fei Yuan ◽  
Qiang Cao ◽  
Huichun Ye ◽  
...  
Keyword(s):  
Field Experiments ◽  
Stem Elongation ◽  
N Uptake ◽  
Growth Stages ◽  
Cold Regions ◽  
N Nutrition ◽  
N Concentration ◽  
Field Samples ◽  
Different Growth Stages ◽  
N Status

Precision nitrogen (N) management requires an accurate and timely in-season assessment of crop N status. The proximal fluorescence sensor Multiplex®3 is a promising tool for monitoring crop N status. It performs a non-destructive estimation of plant chlorophyll, flavonol, and anthocyanin contents, which are related to plant N status. The objective of this study was to evaluate the potential of proximal fluorescence sensing for N status estimation at different growth stages for rice in cold regions. In 2012 and 2013, paddy rice field experiments with five N supply rates and two varieties were conducted in northeast China. Field samples and fluorescence data were collected in the leaf scale (LS), on-the-go (OG), and above the canopy (AC) modes using Multiplex®3 at the panicle initiation (PI), stem elongation (SE), and heading (HE) stages. The relationships between the Multiplex indices or normalized N sufficient indices (NSI) and five N status indicators (above-ground biomass (AGB), leaf N concentration (LNC), plant N concentration (PNC), plant N uptake (PNU), and N nutrition index (NNI)) were evaluated. Results showed that Multiplex measurements taken using the OG mode were more sensitive to rice N status than those made in the other two modes in this study. Most of the measured fluorescence indices, especially the N balance index (NBI), simple fluorescence ratios (SFR), blue–green to far-red fluorescence ratio (BRR_FRF), and flavonol (FLAV) were highly sensitive to N status. Strong relationships between these fluorescence indices and N indicators, especially the LNC, PNC, and NNI were revealed, with coefficients of determination (R2) ranging from 0.40 to 0.78. The N diagnostic results indicated that the normalized N sufficiency index based on NBI under red illumination (NBI_RNSI) and FLAV achieved the highest diagnostic accuracy rate (90%) at the SE and HE stages, respectively, while NBI_RNSI showed the highest diagnostic consistency across growth stages. The study concluded that the Multiplex sensor could be used to reliably estimate N nutritional status for rice in cold regions, especially for the estimation of LNC, PNC, and NNI. The normalized N sufficiency indices based on the Multiplex indices could further improve the accuracy of N nutrition diagnosis by reducing the influences of inter-annual variations and different varieties, as compared with the original Multiplex indices.

Proximal fluorescence sensing for in-season diagnosis of rice nitrogen status

2017 ◽  
Vol 8 (2) ◽  
pp. 343-348 ◽  
Author(s):  
S. Huang ◽  
Y. Miao ◽  
F. Yuan ◽  
Q. Cao ◽  
H. Ye ◽  
...  
Keyword(s):  
Stem Elongation ◽  
N Uptake ◽  
Growth Stages ◽  
Fluorescence Sensing ◽  
N Nutrition ◽  
N Concentration ◽  
Field Samples ◽  
Highly Correlated ◽  
Different Growth Stages ◽  
N Status

The objective of this study was to evaluate the potential of using Multiplex 3, a hand-held canopy fluorescence sensor, to determine rice nitrogen (N) status at different growth stages. In 2013, a paddy rice field experiment with five N fertilizer treatments and two varieties was conducted in Northeast China. Field samples and fluorescence data were collected simultaneously at the panicle initiation (PI), stem elongation (SE), and heading (HE) stages. Four N status indicators, leaf N concentration (LNC), plant N concentration (PNC), plant N uptake (PNU) and N nutrition index (NNI), were determined. The preliminary results indicated that different N application rates significantly affected most of the fluorescence variables, especially the simple fluorescence ratios (SFR_G, SFR_R), flavonoid (FLAV), and N balance indices (NBI_G, NBI_R). These variables were highly correlated with N status indicators. More studies are needed to further evaluate the accuracy of rice N status diagnosis using fluorescence sensing at different growth stages.

scholarly journals Evaluation of Three Portable Optical Sensors for Non-Destructive Diagnosis of Nitrogen Status in Winter Wheat

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5579
Author(s):  
Jie Jiang ◽  
Cuicun Wang ◽  
Hui Wang ◽  
Zhaopeng Fu ◽  
Qiang Cao ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Optical Sensors ◽  
Accurate Estimation ◽  
Growth Stages ◽  
N Accumulation ◽  
N Nutrition ◽  
N Concentration ◽  
Non Destructive ◽  
N Status ◽  
Leaf N

The accurate estimation and timely diagnosis of crop nitrogen (N) status can facilitate in-season fertilizer management. In order to evaluate the performance of three leaf and canopy optical sensors in non-destructively diagnosing winter wheat N status, three experiments using seven wheat cultivars and multi-N-treatments (0–360 kg N ha−1) were conducted in the Jiangsu province of China from 2015 to 2018. Two leaf sensors (SPAD 502, Dualex 4 Scientific+) and one canopy sensor (RapidSCAN CS-45) were used to obtain leaf and canopy spectral data, respectively, during the main growth period. Five N indicators (leaf N concentration (LNC), leaf N accumulation (LNA), plant N concentration (PNC), plant N accumulation (PNA), and N nutrition index (NNI)) were measured synchronously. The relationships between the six sensor-based indices (leaf level: SPAD, Chl, Flav, NBI, canopy level: NDRE, NDVI) and five N parameters were established at each growth stages. The results showed that the Dualex-based NBI performed relatively well among four leaf-sensor indices, while NDRE of RS sensor achieved a best performance due to larger sampling area of canopy sensor for five N indicators estimation across different growth stages. The areal agreement of the NNI diagnosis models ranged from 0.54 to 0.71 for SPAD, 0.66 to 0.84 for NBI, and 0.72 to 0.86 for NDRE, and the kappa coefficient ranged from 0.30 to 0.52 for SPAD, 0.42 to 0.72 for NBI, and 0.53 to 0.75 for NDRE across all growth stages. Overall, these results reveal the potential of sensor-based diagnosis models for the rapid and non-destructive diagnosis of N status.

scholarly journals Canopy Fluorescence Sensing for in-Season Maize Nitrogen Status Diagnosis

2021 ◽  
Vol 13 (24) ◽  
pp. 5141
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Fei Yuan ◽  
Krzysztof Kusnierek
Keyword(s):  
Linear Regression ◽  
Growth Stage ◽  
N Uptake ◽  
Bare Soil ◽  
Estimation Accuracy ◽  
Growth Stages ◽  
Fluorescence Sensing ◽  
N Nutrition ◽  
Regression Methods ◽  
N Status

Accurate assessment of crop nitrogen (N) status and understanding the N demand are considered essential in precision N management. Chlorophyll fluorescence is unsusceptible to confounding signals from underlying bare soil and is closely related to plant photosynthetic activity. Therefore, fluorescence sensing is considered a promising technology for monitoring crop N status, even at an early growth stage. The objectives of this study were to evaluate the potential of using Multiplex® 3, a proximal canopy fluorescence sensor, to detect N status variability and to quantitatively estimate N status indicators at four key growth stages of maize. The sensor measurements were performed at different growth stages, and three different regression methods were compared to estimate plant N concentration (PNC), plant N uptake (PNU), and N nutrition index (NNI). The results indicated that the induced differences in maize plant N status were detectable as early as the V6 growth stage. The first method based on simple regression (SR) and the Multiplex sensor indices normalized by growing degree days (GDD) or N sufficiency index (NSI) achieved acceptable estimation accuracy (R2 = 0.73–0.87), showing a good potential of canopy fluorescence sensing for N status estimation. The second method using multiple linear regression (MLR), fluorescence indices and GDDs had the lowest modeling accuracy (R2 = 0.46–0.79). The third tested method used a non-linear regression approach in the form of random forest regression (RFR) based on multiple sensor indices and GDDs. This approach achieved the best estimation accuracy (R2 = 0.84–0.93) and the most accurate diagnostic result.

scholarly journals Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Fluorescence Sensor ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Fluorescence Sensors ◽  
N Application ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Status ◽  
Leaf N

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

scholarly journals Development of Chlorophyll-Meter-Index-Based Dynamic Models for Evaluation of High-Yield Japonica Rice Production in Yangtze River Reaches

Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 106 ◽  
Author(s):  
Ke Zhang ◽  
Xiaojun Liu ◽  
Syed Tahir Ata-Ul-Karim ◽  
Jingshan Lu ◽  
Brian Krienke ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
High Yield ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Rice Grain ◽  
Japonica Rice ◽  
Ripening Period ◽  
The Third ◽  
Different Growth Stages

Accurate estimation of the nitrogen (N) spatial distribution of rice (Oryza sativa L.) is imperative when it is sought to maintain regional and global carbon balances. We systematically evaluated the normalized differences of the soil and plant analysis development (SPAD) index (the normalized difference SPAD indexes, NDSIs) between the upper (the first and second leaves from the top), and lower (the third and fourth leaves from the top) leaves of Japonica rice. Four multi-location, multi-N rate (0–390 kg ha−1) field experiments were conducted using seven Japonica rice cultivars (9915, 27123, Wuxiangjing14, Wunyunjing19, Wunyunjing24, Liangyou9, and Yongyou8). Growth analyses were performed at different growth stages ranging from tillering (TI) to the ripening period (RP). We measured leaf N concentration (LNC), the N nutrition index (NNI), the NDSI, and rice grain yield at maturity. The relationships among the NDSI, LNC, and NNI at different growth stages showed that the NDSI values of the third and fourth fully expanded leaves more reliably reflected the N nutritional status than those of the first and second fully expanded leaves (LNC: NDSIL3,4, R2 > 0.81; NDSIothers, 0.77 > R2 > 0.06; NNI: NDSIL3,4, R2 > 0.83; NDSIothers, 0.76 > R2 > 0.07; all p < 0.01). Two new diagnostic models based on the NDSIL3,4 (from the tillering to the ripening period) can be used for effective diagnosis of the LNC and NNI, which exhibited reasonable distributions of residuals (LNC: relative root mean square error (RRMSE) = 0.0683; NNI: RRMSE = 0.0688; p < 0.01). The relationship between grain yield, predicted yield, and NDSIL3,4 were established during critical growth stages (from the stem elongation to the heading stages; R2 = 0.53, p < 0.01, RRMSE = 0.106). An NDSIL3,4 high-yield change curve was drawn to describe critical NDSIL3,4 values for a high-yield target (10.28 t ha−1). Furthermore, dynamic-critical curve models based on the NDSIL3,4 allowed a precise description of rice N status, facilitating the timing of fertilization decisions to optimize yields in the intensive rice cropping systems of eastern China.

Effect of silicon at panicle initiation on the growth of rice (Var. ADT-36) plants at different growth stages

2002 ◽  
Vol 50 (2) ◽  
pp. 179-184
Author(s):  
P. M. Arthanari ◽  
P. Gnanamoorthy ◽  
S. Ramasamy
Keyword(s):  
Tamil Nadu ◽  
Dry Matter ◽  
Field Experiments ◽  
Dry Matter Production ◽  
Growth Stages ◽  
Maturity Stage ◽  
Maturity Stages ◽  
Matter Production ◽  
Initiation Stage ◽  
Different Growth Stages

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India during the Rabi (November 1997-March 1998) and Kharif (July 1998-November 1998) seasons to identify the effect of silicon at panicle initiation on the growth of rice plant (Variety ADT-36) at different growth stages. Furnace slag was applied as a silicon source at 2 t/ha at the panicle initiation stage along with other nutrients. The dry matter production was recorded at the active tillering, panicle initiation, booting, flowering, one week after flowering and maturity stages in both the seasons. The total dry matter production was greater in the Kharif season than in the Rabi season. The application of slag at the panicle initiation stage along with N and K at the flowering stage had a significant influence over the dry matter production. A similar trend was observed in both the seasons. The silicon uptake was recorded at the panicle initiation and maturity stages. About 30-40% of the silicon absorbed during the early stages and the maturity stage was present in the shoot, whereas 20-30 % of the silicon absorbed during the maturity stages was present in the leaf blades. Based on the results, it is concluded that the supply of silicon during the panicle initiation stage is most important for plant growth.

SENSITIVITY OF CROP PLANTS TO WATER STRESS AT SPECIFIC DEVELOPMENTAL STAGES: REEVALUATION OF EXPERIMENTAL FINDINGS

1995 ◽  
Vol 43 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Zvi Plaut
Keyword(s):  
Water Stress ◽  
Irrigation Water ◽  
Field Experiments ◽  
Developmental Stages ◽  
Growth Period ◽  
Soluble Solids ◽  
Growth Stages ◽  
Mild Stress ◽  
Uniform Reduction ◽  
Different Growth Stages

It has been suggested that in many crops differences in sensitivity to water stress occur at different growth stages. Since identical amounts of water may be applied, irrespective of whether a crop is exposed to relatively severe and short periods of stress or to extended periods of mild stress, the responses to such differing conditions should be compared. Unfortunately, such a comparison has not been conducted in most studies on sensitivity to water stress at different growth stages. In the present study, based on three field experiments conducted for different purposes, such a comparison was made for three crops: corn, sunflower, and tomato. In corn, distinct responses of ear and kernel yields to the timing of water stress were found. Withdrawal of irrigation water during flowering and cob formation resulted in greater yield losses than during other stages, indicating that this is a critical growth stage. However, slight and uniform reduction of water during the entire growth period resulted in significantly less damage to kernel or ear production, although the total amount of water applied was similar to that under staged withdrawal. In sunflowers, the withdrawal of irrigation water even at noncritical growth stages caused a more marked reduction in grain yield than did a uniform reduction throughout the entire season. In tomatoes, on the other hand, the withdrawal of irrigation water during specific growth stages caused minimal damage to fruit and total soluble solids yield as compared with fully irrigated control; reduction of irrigation water throughout the season brought about a significant decrease in yield. The difference between these crops is interpreted on the basis of the determinance of their floral meristems.

Effects of irrigation and nitrogen on the yield components of fennel (Foeniculum vulgare Mill.)

1994 ◽  
Vol 34 (6) ◽  
pp. 845 ◽  
Author(s):  
M Buntain ◽  
B Chung
Keyword(s):  
Yield Components ◽  
Stem Elongation ◽  
Growth Stages ◽  
Full Irrigation ◽  
Flowering Stage ◽  
Foeniculum Vulgare ◽  
Late Flowering ◽  
Whole Plant ◽  
Dry Conditions ◽  
Different Growth Stages

A field experiment was conducted to study the effects of irrigation and nitrogen applied at different growth stages on the oil and anethole yields of fennel (Foeniculum vulgare Mill.), and its yield components. Irrigation increased the yield of whole plant dry matter, with the stem elongation stage being the most sensitive. Full irrigation and irrigation applied during the flowering and late flowering growth stages increased umbel and oil yields. Irrigation during the late flowering stage made the greatest contribution to oil yield, accounting for >80% of the yield due to full irrigation. This was attributed to the concurrent timing of irrigation during the late flowering stage with dry conditions and the development of the main oil-bearing structures, the secondary and tertiary umbels. Irrigation had no significant effect on the anethole concentration of the oil. The best economic return was achieved by irrigating during the late flowering stage. There was no significant effect of nitrogen on any of the yield components measured in this study.

scholarly journals The Nitrogen Use Efficiency: Meaning and Sources of Variation—Case Studies on Three Vegetable Crops in Central Italy

2011 ◽  
Vol 21 (3) ◽  
pp. 266-273 ◽  
Author(s):  
Paolo Benincasa ◽  
Marcello Guiducci ◽  
Francesco Tei
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
Irrigation Management ◽  
Central Italy ◽  
Utilization Efficiency ◽  
Fertilizer N ◽  
Application Method ◽  
N Concentration ◽  
Sources Of Variation ◽  
Use Efficiency

Nitrogen (N) use efficiency (NUE) of crops is examined by taking into account both plant N uptake efficiency, focusing on the recovery of fertilizer-N, and the utilization efficiency of the absorbed N. The latter is further analyzed as the overall effect of the absorbed N on crop leaf area, light absorption, photosynthesis, crop growth, biomass partitioning, and yield. The main sources of variation for the NUE of crops are considered, and several of them are discussed based on results from field experiments carried out at the University of Perugia (central Italy) between 1991 and 2008 on sweet pepper (Capsicum annuum), lettuce (Lactuca sativa), and processing tomato (Solanum lycopersicum). More specifically, the effects of species, cultivar, fertilizer-N rate, form and application method (mineral and organic fertilization, green manuring, fertigation frequency), and sink limitation are reported. Implications for residual N in the soil and leaching risks are also discussed. The fertilizer-N rate is the main factor affecting crop NUE for a given irrigation management and rainfall regime. Indeed, avoiding over fertilization is the first and primary means to match a high use efficiency and economic return of fertilizer-N with limited environmental risks from nitrate leaching. The form and application method of fertilizer-N also may affect the NUE, especially in the case of limiting or overabundant N supply. Particularly, high fertigation frequency increased the recovery of fertilizer-N by the crop. It is suggested that species-specific curves for critical N concentration (i.e., the minimum N concentration that allows the maximum growth) can be the reference to calibrate the quick tests used to guide dynamic fertilization management, which is essential to achieve both the optimal crop N nutritional status and the maximum NUE.

Effect of spad techniques and planting density on 'Y' leaf nitrogen concentration in transplanted rice

2004 ◽  
Vol 52 (1) ◽  
pp. 95-104 ◽  
Author(s):  
P. Janaki ◽  
T. M. Thiyagarajan
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Nitrogen Concentration ◽  
Planting Density ◽  
Growth Stages ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Management ◽  
Leaf N

Field experiments were conducted in June-September 1998 and 1999 with rice variety ASD18 at the wetland farm of Tamil Nadu Agricultural University, in Coimbatore, India to examine variations in 'Y' leaf (youngest fully expanded leaf) N concentration as influenced by different planting densities and N management strategies in a split plot design. The main plot consisted of three plant populations (33, 66 and 100 hills m-2) and the sub-plots treatments of five N management approaches. The results revealed that the nitrogen concentration progressively declined with growth, the decline being steep up to 35 days after transplanting, wereafter the values became almost linear up to the flowering stage in all the treatments. The mean 'Y' leaf N was found to be significantly higher at 33 hills m-2 (45.1 g kg-1), while the other two densities were on par (42.9 g kg-1). When N application was based on chlorophyll meter (SPAD) values the leaf N concentration was maintained at a level of 39.2 to 51.9 g kg-1 to produce maximum grain yield. A significant correlation was observed between the chlorophyll meter values and 'Y' leaf N concentrations at various days after transplanting (r values ranged from 0.57* to 0.83**), while the correlation was highly significant during the major physiological growth stages. Though the 'Y' leaf content was significantly higher in the treatment involving Sesbania rostrata green manuring + 150 kg N applied in splits, the grain yield produced was on par in all the N applied treatments. A highly significant correlation was observed between the grain yield and both 'Y' leaf N content and SPAD values during various growth periods.

Sign in / Sign up

Export Citation Format

Share Document