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Syed Tahir Ataulkarim - One of the best experts on this subject based on the ideXlab platform.

  • determination of critical nitrogen concentration and Dilution Curve based on leaf area index for summer maize
    Field Crops Research, 2018
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Dongfeng Ning, Junfu Xiao, Aiwang Duan, Xiaolong Wang, Weiqiang Zhang, Yanhao Lian
    Abstract:

    Abstract Injudicious nitrogen (N) fertilizer application has increased the risk of environmental pollution and decreased grain yields, farm profits, and N use efficiency. The plant based N diagnostic tools can be used to optimize N management of summer maize production. This study was designed to develop and validate a leaf area index (LAI) based critical N (N c ) Dilution Curve and to establish a theoretical framework to link the relationship of LAI and plant dry matter (DM) based Curves, as well as to compare the differences between LAI, plant DM and growth stage-based N c Curves. Six field experiments were set with a range of N application rates (0–320 kg N ha −1 ) and plant densities (6 to 8 × 10 4 plants ha -1 ) using four summer maize cultivars (Zhengdan958, Denghai605, Xundan20, and Denghai661) in Henan province of China. LAI and plant N concentration (PNC) were determined from V6 to R1 stages in each experiment for the development of the N c Curve. LAI and PNC ranged from 1.28 to 6.12 and 1.34% to 3.31% under different N levels, respectively. Allometric relationships between LAI, plant DM, and critical N uptake (N uc ) were developed under non-N-limiting treatments. The relationship between N c and LAI during vegetative growth period was described by a power function (N c  = 3.84LAI −0.45 ). N nutrition index (NNI) increased with the increasing N application rate and ranged from 0.56 and 1.23 across different N treatments. Our results validated that plant N uptake was proportional with LAI, and the allometric parameter between LAI and plant DM of summer maize was close to the theoretical value 2/3. The newly developed LAI-based N c Curve could identify plant N status (N-limiting and non-N-limiting) during key N requirement period of summer maize and can be used for precision N management for summer maize grown in China.

  • in season assessment of grain protein and amylose content in rice using critical nitrogen Dilution Curve
    European Journal of Agronomy, 2017
    Co-Authors: Syed Tahir Ataulkarim, Qiang Cao, Yan Zhu, Weixing Cao, Muhammad Ishaq Asif Rehmani, Liang Tang
    Abstract:

    Abstract Effective nitrogen (N) management strategies ensure optimal N status in rice (Oryza sativa L.) plants for improving crop growth and grain quality with optimal N use efficiency. In-season plant N status affects rice grain quality. The critical N (Nc) Dilution Curves have been applied for predicting in-season nitrogen requirement (NR) and grain yield in rice, however, its application for estimating rice grain quality at harvest is yet to be tested. This research was endeavored to establish the quantitative relationships of protein content (PC) and amylose content (AC) with nitrogen nutrition index (NNI), accumulated nitrogen deficit (AND), and NR at various growth stages during vegetative growth period of rice and to validate these relationships in Japonica and Indica rice ecotypes. Five multi-locational field trials with five rice cultivars and varied N application rates were carried out in eastern China. The quantitative relationships of PC and AC with NNI, AND, and NR at various growth stages in both rice ecotypes were highly significant (for Japonica and Indica, R2 > 0.88 and 0.85 for PC, R2 > 0.85 and 0.81 for AC, respectively). The strongest relations were observed for both rice ecotypes at later vegetative growth stages and periods. The validation of the developed quantitative relationships with the independent dataset revealed a solid model performance, especially during later vegetative growth period (R2 > 0.90, root mean square error

  • development of a critical nitrogen Dilution Curve based on leaf dry matter for summer maize
    Field Crops Research, 2017
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Zhandong Liu, Dongfeng Ning, Junfu Xiao, Zugui Liu, Anzhen Qin, Jiqin Nan, Aiwang Duan
    Abstract:

    Abstract Accurate diagnosis of nitrogen (N) fertilizer required for crop growth can serve as a guide for N management by improving N use efficiency and grain yields. The critical N concentration (Nc), the minimum N required for maximal crop growth has been widely used to determine crop N status. Nc Dilution Curves have been determined in several crops including summer maize on plant dry matter (DM) basis, yet no attempt has been made to determine the Nc Dilution Curve on the basis of leaf dry matter (LDM) in summer maize. The present study aimed to determine a Nc Dilution Curve based on LDM for in-season assessment of crop N status in summer maize. Six field experiments were performed with four summer maize cultivars using varied N fertilizer rates ranging from 0 to 320 kg N ha−1. The leaf Nc Curve was described by the equation: Nc = 3.45LDM−0.22, when LDM ranged from 1.18 to 3.45 t ha−1. For LDM

  • development of a critical nitrogen Dilution Curve of double cropping rice in south china
    Frontiers in Plant Science, 2017
    Co-Authors: Xiaolei Qiu, Syed Tahir Ataulkarim, Xiaojun Liu, Qiang Cao, Yan Zhu, Weixing Cao, Liang Tang
    Abstract:

    The concept of critical nitrogen (Nc) concentration can be implemented to diagnose in-season plant nitrogen (N) status for optimizing N fertilizer management. The Nc Dilution Curves have been established for rice (Oryza sativa L.) grown in different climatic regions, yet no attempt has been made to develop the Nc Dilution Curve for double cropping rice regions. This study was undertaken to develop the Nc Dilution Curves for double cropping rice in south China for assessment of in-season N status and to establish the relationships N nutrition index (NNI) and relative yield (RY) for in-season prediction of rice grain yield. Three different N application rate field experiments using six Indica rice varieties, including two early rice hybrids and four late rice hybrids were carried out in east China. The Nc Dilution Curves based on whole plant N concentration were determined and described as, Nc = 3.37 W-0.44 for early rice and Nc = 3.69 W-0.34 for late rice. The constant N concentration at early growth stage was 3.31 and 3.15% DM for early and late rice, respectively. Late rice showed a higher capacity of N accumulation and a lower rate of N decline per unit shoot biomass as compared to early rice. The Curves for present study were different from the existing reference Curves for Indica and Japonica rice grown in different rice growing regions. Integrated N nutrition index (NNIint) based on Nc was used to estimate RY at different growth periods using linear regression functions. The results showed that the critical Curves and relationship between NNIint and RY could be used as a reliable indicator of N status diagnosis, grain yield prediction as well as to provide technical support in N management for double cropping rice in south China.

  • development of critical nitrogen Dilution Curve in rice based on leaf dry matter
    European Journal of Agronomy, 2014
    Co-Authors: Xia Yao, Syed Tahir Ataulkarim, Xiaojun Liu, Yan Zhu, Yongchao Tian, Weixing Cao
    Abstract:

    Abstract The critical nitrogen ( N c ), defined as the minimum N concentration required for maximum growth, is proposed for diagnosis of the in-season N status in crop plants. It has been established for several crops including rice on whole-plant dry matter (DM) basis but has not been determined for canopy leaf basis. This research was undertaken to develop a new N c Dilution Curve based on leaf dry matter ( L DM ) and to assess its applicability to estimate the level of N nutrition for Japonica rice in east China. Three field experiments were conducted with varied N rates (0–360 kg N ha −1 ) and three Japonica rice ( Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis and leaf N determination. The N c Dilution Curve on leaf N concentration was described by the equation N c  = 3.76 W −0.218 , when L DM ranged from 0.67 to 4.25 t ha −1 . However, for L DM −1 , the constant critical value N c  = 4.09% L DM was applied. This N c Dilution Curve on L DM basis was slightly higher than the Curves on plant DM basis in Japonica rice, yet both lower than the reference Curve of high yielding Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit ( N and ) of leaves ranged from 0.65 to 1.06 and 79.62 to −6.39 kg ha −1 , respectively, during main growth stages under varied N rates in 2010 and 2011. The results indicate that the present N c Dilution Curve and derived NNI and N and adequately identified the situations of N-limiting and non-N-limiting nutrition in two rice varieties and could be used as reliable indicators of N status during growth of Japonica rice in east China.

Ben Zhao - One of the best experts on this subject based on the ideXlab platform.

  • determination of critical nitrogen concentration and Dilution Curve based on leaf area index for summer maize
    Field Crops Research, 2018
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Dongfeng Ning, Junfu Xiao, Aiwang Duan, Xiaolong Wang, Weiqiang Zhang, Yanhao Lian
    Abstract:

    Abstract Injudicious nitrogen (N) fertilizer application has increased the risk of environmental pollution and decreased grain yields, farm profits, and N use efficiency. The plant based N diagnostic tools can be used to optimize N management of summer maize production. This study was designed to develop and validate a leaf area index (LAI) based critical N (N c ) Dilution Curve and to establish a theoretical framework to link the relationship of LAI and plant dry matter (DM) based Curves, as well as to compare the differences between LAI, plant DM and growth stage-based N c Curves. Six field experiments were set with a range of N application rates (0–320 kg N ha −1 ) and plant densities (6 to 8 × 10 4 plants ha -1 ) using four summer maize cultivars (Zhengdan958, Denghai605, Xundan20, and Denghai661) in Henan province of China. LAI and plant N concentration (PNC) were determined from V6 to R1 stages in each experiment for the development of the N c Curve. LAI and PNC ranged from 1.28 to 6.12 and 1.34% to 3.31% under different N levels, respectively. Allometric relationships between LAI, plant DM, and critical N uptake (N uc ) were developed under non-N-limiting treatments. The relationship between N c and LAI during vegetative growth period was described by a power function (N c  = 3.84LAI −0.45 ). N nutrition index (NNI) increased with the increasing N application rate and ranged from 0.56 and 1.23 across different N treatments. Our results validated that plant N uptake was proportional with LAI, and the allometric parameter between LAI and plant DM of summer maize was close to the theoretical value 2/3. The newly developed LAI-based N c Curve could identify plant N status (N-limiting and non-N-limiting) during key N requirement period of summer maize and can be used for precision N management for summer maize grown in China.

  • development of a critical nitrogen Dilution Curve based on leaf dry matter for summer maize
    Field Crops Research, 2017
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Zhandong Liu, Dongfeng Ning, Junfu Xiao, Zugui Liu, Anzhen Qin, Jiqin Nan, Aiwang Duan
    Abstract:

    Abstract Accurate diagnosis of nitrogen (N) fertilizer required for crop growth can serve as a guide for N management by improving N use efficiency and grain yields. The critical N concentration (Nc), the minimum N required for maximal crop growth has been widely used to determine crop N status. Nc Dilution Curves have been determined in several crops including summer maize on plant dry matter (DM) basis, yet no attempt has been made to determine the Nc Dilution Curve on the basis of leaf dry matter (LDM) in summer maize. The present study aimed to determine a Nc Dilution Curve based on LDM for in-season assessment of crop N status in summer maize. Six field experiments were performed with four summer maize cultivars using varied N fertilizer rates ranging from 0 to 320 kg N ha−1. The leaf Nc Curve was described by the equation: Nc = 3.45LDM−0.22, when LDM ranged from 1.18 to 3.45 t ha−1. For LDM

  • a new Curve of critical nitrogen concentration based on spike dry matter for winter wheat in eastern china
    PLOS ONE, 2016
    Co-Authors: Ben Zhao, Syed Tahir Atauikarim, Yongchao Tian
    Abstract:

    Diagnosing the status of crop nitrogen (N) helps to optimize crop yield, improve N use efficiency, and reduce the risk of environmental pollution. The objectives of the present study were to develop a critical N (Nc) Dilution Curve for winter wheat (based on spike dry matter [SDM] during the reproductive growth period), to compare this Curve with the existing Nc Dilution Curve (based on plant dry matter [DM] of winter wheat), and to explore its ability to reliably estimate the N status of winter wheat. Four field experiments, using varied N fertilizer rates (0–375 kg ha-1) and six cultivars (Yangmai16, Ningmai13, Ningmai9, Aikang58, Yangmai12, Huaimai 17), were conducted in the Jiangsu province of eastern China. Twenty plants from each plot were sampled to determine the SDM and spike N concentration (SNC) during the reproductive growth period. The spike Nc Curve was described by Nc = 2.85×SDM-0.17, with SDM ranging from 0.752 to 7.233 t ha-1. The newly developed Curve was lower than the Nc Curve based on plant DM. The N nutrition index (NNI) for spike dry matter ranged from 0.62 to 1.1 during the reproductive growth period across the seasons. Relative yield (RY) increased with increasing NNI; however, when NNI was greater than 0.96, RY plateaued and remained stable. The spike Nc Dilution Curve can be used to correctly identify the N nutrition status of winter wheat to support N management during the reproductive growth period for winter wheat in eastern China.

  • determining of a critical Dilution Curve for plant nitrogen concentration in winter barley
    Field Crops Research, 2014
    Co-Authors: Ben Zhao
    Abstract:

    Abstract Accurate forecasting of nitrogen (N) required for plant growth can serve as a guide to improving agricultural practices and regulations. The objectives of this study were to: (i) establish a critical N (N c ) Dilution Curve for winter barley based on the shoot dry matter (DM), (ii) compare this Curve with other N c Dilution Curves of different species, and (iii) assess the plausibility of using this Curve to estimate the N status of winter barley. Four field experiments were conducted with different N application rates. Twenty plants from each plot were sampled from the Feekes 3 to Feekes 10.51 stage for growth analysis. The relationship between N c and shoot DM could be described by a negative power equation, N c  = 4.76DM −0.39 , when shoot DM values were in the range of 1.79– 13.69 t ha −1 . For DM values −1 , however, the constant value N c  = 3.77% was used. The N nutrition index (NNI) ranged from 0.39 to 1.39 from Feekes 3 to Feekes 10.51 under different N application rates from 2005 to 2007. The N c Dilution Curve identified limiting and non-limiting N status of winter barley and could be used as a reliable indicator of in-season N stress of winter barley grown.

Weixing Cao - One of the best experts on this subject based on the ideXlab platform.

  • in season assessment of grain protein and amylose content in rice using critical nitrogen Dilution Curve
    European Journal of Agronomy, 2017
    Co-Authors: Syed Tahir Ataulkarim, Qiang Cao, Yan Zhu, Weixing Cao, Muhammad Ishaq Asif Rehmani, Liang Tang
    Abstract:

    Abstract Effective nitrogen (N) management strategies ensure optimal N status in rice (Oryza sativa L.) plants for improving crop growth and grain quality with optimal N use efficiency. In-season plant N status affects rice grain quality. The critical N (Nc) Dilution Curves have been applied for predicting in-season nitrogen requirement (NR) and grain yield in rice, however, its application for estimating rice grain quality at harvest is yet to be tested. This research was endeavored to establish the quantitative relationships of protein content (PC) and amylose content (AC) with nitrogen nutrition index (NNI), accumulated nitrogen deficit (AND), and NR at various growth stages during vegetative growth period of rice and to validate these relationships in Japonica and Indica rice ecotypes. Five multi-locational field trials with five rice cultivars and varied N application rates were carried out in eastern China. The quantitative relationships of PC and AC with NNI, AND, and NR at various growth stages in both rice ecotypes were highly significant (for Japonica and Indica, R2 > 0.88 and 0.85 for PC, R2 > 0.85 and 0.81 for AC, respectively). The strongest relations were observed for both rice ecotypes at later vegetative growth stages and periods. The validation of the developed quantitative relationships with the independent dataset revealed a solid model performance, especially during later vegetative growth period (R2 > 0.90, root mean square error

  • development of a critical nitrogen Dilution Curve of double cropping rice in south china
    Frontiers in Plant Science, 2017
    Co-Authors: Xiaolei Qiu, Syed Tahir Ataulkarim, Xiaojun Liu, Qiang Cao, Yan Zhu, Weixing Cao, Liang Tang
    Abstract:

    The concept of critical nitrogen (Nc) concentration can be implemented to diagnose in-season plant nitrogen (N) status for optimizing N fertilizer management. The Nc Dilution Curves have been established for rice (Oryza sativa L.) grown in different climatic regions, yet no attempt has been made to develop the Nc Dilution Curve for double cropping rice regions. This study was undertaken to develop the Nc Dilution Curves for double cropping rice in south China for assessment of in-season N status and to establish the relationships N nutrition index (NNI) and relative yield (RY) for in-season prediction of rice grain yield. Three different N application rate field experiments using six Indica rice varieties, including two early rice hybrids and four late rice hybrids were carried out in east China. The Nc Dilution Curves based on whole plant N concentration were determined and described as, Nc = 3.37 W-0.44 for early rice and Nc = 3.69 W-0.34 for late rice. The constant N concentration at early growth stage was 3.31 and 3.15% DM for early and late rice, respectively. Late rice showed a higher capacity of N accumulation and a lower rate of N decline per unit shoot biomass as compared to early rice. The Curves for present study were different from the existing reference Curves for Indica and Japonica rice grown in different rice growing regions. Integrated N nutrition index (NNIint) based on Nc was used to estimate RY at different growth periods using linear regression functions. The results showed that the critical Curves and relationship between NNIint and RY could be used as a reliable indicator of N status diagnosis, grain yield prediction as well as to provide technical support in N management for double cropping rice in south China.

  • development of critical nitrogen Dilution Curve in rice based on leaf dry matter
    European Journal of Agronomy, 2014
    Co-Authors: Xia Yao, Syed Tahir Ataulkarim, Xiaojun Liu, Yan Zhu, Yongchao Tian, Weixing Cao
    Abstract:

    Abstract The critical nitrogen ( N c ), defined as the minimum N concentration required for maximum growth, is proposed for diagnosis of the in-season N status in crop plants. It has been established for several crops including rice on whole-plant dry matter (DM) basis but has not been determined for canopy leaf basis. This research was undertaken to develop a new N c Dilution Curve based on leaf dry matter ( L DM ) and to assess its applicability to estimate the level of N nutrition for Japonica rice in east China. Three field experiments were conducted with varied N rates (0–360 kg N ha −1 ) and three Japonica rice ( Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis and leaf N determination. The N c Dilution Curve on leaf N concentration was described by the equation N c  = 3.76 W −0.218 , when L DM ranged from 0.67 to 4.25 t ha −1 . However, for L DM −1 , the constant critical value N c  = 4.09% L DM was applied. This N c Dilution Curve on L DM basis was slightly higher than the Curves on plant DM basis in Japonica rice, yet both lower than the reference Curve of high yielding Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit ( N and ) of leaves ranged from 0.65 to 1.06 and 79.62 to −6.39 kg ha −1 , respectively, during main growth stages under varied N rates in 2010 and 2011. The results indicate that the present N c Dilution Curve and derived NNI and N and adequately identified the situations of N-limiting and non-N-limiting nutrition in two rice varieties and could be used as reliable indicators of N status during growth of Japonica rice in east China.

  • development of critical nitrogen Dilution Curve of japonica rice in yangtze river reaches
    Field Crops Research, 2013
    Co-Authors: Syed Tahir Ataulkarim, Xiaojun Liu, Weixing Cao, Xia Yao, Yan Zhu
    Abstract:

    Abstract Plant-based analytical techniques of nitrogen (N) nutrition, established on the concept of critical nitrogen (N c ), can be used to diagnose the in-season N status of rice, which in turns can provide understanding of N nutrition and serve as a guide for the profitability and sustainability of agricultural production system. The objectives of present study were to develop an appropriate N c Curve for Japonica rice, to compare this Curve with existing N c Dilution Curve for Indica rice and to assess its plausibility to estimate the level of N nutrition for rice crop in east China. Three field experiments were conducted with varied N rates (0–360 kg N ha −1 ) in three Japonica rice ( Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis. The N c Dilution Curve for rice, based on whole-plant N concentration, was described by the equation (N c  = 3.53 W −0.28 ), when aboveground biomass ranged from 1.55 to 12.37 t ha −1 . However, for above-ground biomass −1 , the constant critical value N c  = 3.05% DM was applied, which was independent of aboveground biomass. Our N c Dilution Curve was lower than the existing Curve of Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit (N and ) ranged from 0.58 to 1.06 and 127 to −12 kg ha −1 , respectively, during main development stages under different N treatments in 2010 and 2011. Different N fertilizations were suggested for unit NNI increase or unit N and decrease at different stages. LXY-18 have more N assimilation tendency than WXJ-14 for satisfying rice growth for same dry matter. The N c Dilution Curve, resulting NNI and N and , adequately identified situations of limiting and non-limiting N nutrition and could be used as a reliable indicator of N stress during the growing season of Japonica rice in east China.

Yan Zhu - One of the best experts on this subject based on the ideXlab platform.

  • in season assessment of grain protein and amylose content in rice using critical nitrogen Dilution Curve
    European Journal of Agronomy, 2017
    Co-Authors: Syed Tahir Ataulkarim, Qiang Cao, Yan Zhu, Weixing Cao, Muhammad Ishaq Asif Rehmani, Liang Tang
    Abstract:

    Abstract Effective nitrogen (N) management strategies ensure optimal N status in rice (Oryza sativa L.) plants for improving crop growth and grain quality with optimal N use efficiency. In-season plant N status affects rice grain quality. The critical N (Nc) Dilution Curves have been applied for predicting in-season nitrogen requirement (NR) and grain yield in rice, however, its application for estimating rice grain quality at harvest is yet to be tested. This research was endeavored to establish the quantitative relationships of protein content (PC) and amylose content (AC) with nitrogen nutrition index (NNI), accumulated nitrogen deficit (AND), and NR at various growth stages during vegetative growth period of rice and to validate these relationships in Japonica and Indica rice ecotypes. Five multi-locational field trials with five rice cultivars and varied N application rates were carried out in eastern China. The quantitative relationships of PC and AC with NNI, AND, and NR at various growth stages in both rice ecotypes were highly significant (for Japonica and Indica, R2 > 0.88 and 0.85 for PC, R2 > 0.85 and 0.81 for AC, respectively). The strongest relations were observed for both rice ecotypes at later vegetative growth stages and periods. The validation of the developed quantitative relationships with the independent dataset revealed a solid model performance, especially during later vegetative growth period (R2 > 0.90, root mean square error

  • development of a critical nitrogen Dilution Curve of double cropping rice in south china
    Frontiers in Plant Science, 2017
    Co-Authors: Xiaolei Qiu, Syed Tahir Ataulkarim, Xiaojun Liu, Qiang Cao, Yan Zhu, Weixing Cao, Liang Tang
    Abstract:

    The concept of critical nitrogen (Nc) concentration can be implemented to diagnose in-season plant nitrogen (N) status for optimizing N fertilizer management. The Nc Dilution Curves have been established for rice (Oryza sativa L.) grown in different climatic regions, yet no attempt has been made to develop the Nc Dilution Curve for double cropping rice regions. This study was undertaken to develop the Nc Dilution Curves for double cropping rice in south China for assessment of in-season N status and to establish the relationships N nutrition index (NNI) and relative yield (RY) for in-season prediction of rice grain yield. Three different N application rate field experiments using six Indica rice varieties, including two early rice hybrids and four late rice hybrids were carried out in east China. The Nc Dilution Curves based on whole plant N concentration were determined and described as, Nc = 3.37 W-0.44 for early rice and Nc = 3.69 W-0.34 for late rice. The constant N concentration at early growth stage was 3.31 and 3.15% DM for early and late rice, respectively. Late rice showed a higher capacity of N accumulation and a lower rate of N decline per unit shoot biomass as compared to early rice. The Curves for present study were different from the existing reference Curves for Indica and Japonica rice grown in different rice growing regions. Integrated N nutrition index (NNIint) based on Nc was used to estimate RY at different growth periods using linear regression functions. The results showed that the critical Curves and relationship between NNIint and RY could be used as a reliable indicator of N status diagnosis, grain yield prediction as well as to provide technical support in N management for double cropping rice in south China.

  • development of critical nitrogen Dilution Curve in rice based on leaf dry matter
    European Journal of Agronomy, 2014
    Co-Authors: Xia Yao, Syed Tahir Ataulkarim, Xiaojun Liu, Yan Zhu, Yongchao Tian, Weixing Cao
    Abstract:

    Abstract The critical nitrogen ( N c ), defined as the minimum N concentration required for maximum growth, is proposed for diagnosis of the in-season N status in crop plants. It has been established for several crops including rice on whole-plant dry matter (DM) basis but has not been determined for canopy leaf basis. This research was undertaken to develop a new N c Dilution Curve based on leaf dry matter ( L DM ) and to assess its applicability to estimate the level of N nutrition for Japonica rice in east China. Three field experiments were conducted with varied N rates (0–360 kg N ha −1 ) and three Japonica rice ( Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis and leaf N determination. The N c Dilution Curve on leaf N concentration was described by the equation N c  = 3.76 W −0.218 , when L DM ranged from 0.67 to 4.25 t ha −1 . However, for L DM −1 , the constant critical value N c  = 4.09% L DM was applied. This N c Dilution Curve on L DM basis was slightly higher than the Curves on plant DM basis in Japonica rice, yet both lower than the reference Curve of high yielding Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit ( N and ) of leaves ranged from 0.65 to 1.06 and 79.62 to −6.39 kg ha −1 , respectively, during main growth stages under varied N rates in 2010 and 2011. The results indicate that the present N c Dilution Curve and derived NNI and N and adequately identified the situations of N-limiting and non-N-limiting nutrition in two rice varieties and could be used as reliable indicators of N status during growth of Japonica rice in east China.

  • development of critical nitrogen Dilution Curve of japonica rice in yangtze river reaches
    Field Crops Research, 2013
    Co-Authors: Syed Tahir Ataulkarim, Xiaojun Liu, Weixing Cao, Xia Yao, Yan Zhu
    Abstract:

    Abstract Plant-based analytical techniques of nitrogen (N) nutrition, established on the concept of critical nitrogen (N c ), can be used to diagnose the in-season N status of rice, which in turns can provide understanding of N nutrition and serve as a guide for the profitability and sustainability of agricultural production system. The objectives of present study were to develop an appropriate N c Curve for Japonica rice, to compare this Curve with existing N c Dilution Curve for Indica rice and to assess its plausibility to estimate the level of N nutrition for rice crop in east China. Three field experiments were conducted with varied N rates (0–360 kg N ha −1 ) in three Japonica rice ( Oryza sativa L.) hybrids, Lingxiangyou-18 (LXY-18), Wuxiangjing-14 (WXJ-14) and Wuyunjing (WYJ) in Jiangsu province of east China. Five hills from each plot were sampled from active tillering to heading for growth analysis. The N c Dilution Curve for rice, based on whole-plant N concentration, was described by the equation (N c  = 3.53 W −0.28 ), when aboveground biomass ranged from 1.55 to 12.37 t ha −1 . However, for above-ground biomass −1 , the constant critical value N c  = 3.05% DM was applied, which was independent of aboveground biomass. Our N c Dilution Curve was lower than the existing Curve of Indica rice in tropics. The N nutrition index (NNI) and accumulated N deficit (N and ) ranged from 0.58 to 1.06 and 127 to −12 kg ha −1 , respectively, during main development stages under different N treatments in 2010 and 2011. Different N fertilizations were suggested for unit NNI increase or unit N and decrease at different stages. LXY-18 have more N assimilation tendency than WXJ-14 for satisfying rice growth for same dry matter. The N c Dilution Curve, resulting NNI and N and , adequately identified situations of limiting and non-limiting N nutrition and could be used as a reliable indicator of N stress during the growing season of Japonica rice in east China.

Aiwang Duan - One of the best experts on this subject based on the ideXlab platform.

  • determination of critical nitrogen concentration and Dilution Curve based on leaf area index for summer maize
    Field Crops Research, 2018
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Dongfeng Ning, Junfu Xiao, Aiwang Duan, Xiaolong Wang, Weiqiang Zhang, Yanhao Lian
    Abstract:

    Abstract Injudicious nitrogen (N) fertilizer application has increased the risk of environmental pollution and decreased grain yields, farm profits, and N use efficiency. The plant based N diagnostic tools can be used to optimize N management of summer maize production. This study was designed to develop and validate a leaf area index (LAI) based critical N (N c ) Dilution Curve and to establish a theoretical framework to link the relationship of LAI and plant dry matter (DM) based Curves, as well as to compare the differences between LAI, plant DM and growth stage-based N c Curves. Six field experiments were set with a range of N application rates (0–320 kg N ha −1 ) and plant densities (6 to 8 × 10 4 plants ha -1 ) using four summer maize cultivars (Zhengdan958, Denghai605, Xundan20, and Denghai661) in Henan province of China. LAI and plant N concentration (PNC) were determined from V6 to R1 stages in each experiment for the development of the N c Curve. LAI and PNC ranged from 1.28 to 6.12 and 1.34% to 3.31% under different N levels, respectively. Allometric relationships between LAI, plant DM, and critical N uptake (N uc ) were developed under non-N-limiting treatments. The relationship between N c and LAI during vegetative growth period was described by a power function (N c  = 3.84LAI −0.45 ). N nutrition index (NNI) increased with the increasing N application rate and ranged from 0.56 and 1.23 across different N treatments. Our results validated that plant N uptake was proportional with LAI, and the allometric parameter between LAI and plant DM of summer maize was close to the theoretical value 2/3. The newly developed LAI-based N c Curve could identify plant N status (N-limiting and non-N-limiting) during key N requirement period of summer maize and can be used for precision N management for summer maize grown in China.

  • development of a critical nitrogen Dilution Curve based on leaf dry matter for summer maize
    Field Crops Research, 2017
    Co-Authors: Ben Zhao, Syed Tahir Ataulkarim, Zhandong Liu, Dongfeng Ning, Junfu Xiao, Zugui Liu, Anzhen Qin, Jiqin Nan, Aiwang Duan
    Abstract:

    Abstract Accurate diagnosis of nitrogen (N) fertilizer required for crop growth can serve as a guide for N management by improving N use efficiency and grain yields. The critical N concentration (Nc), the minimum N required for maximal crop growth has been widely used to determine crop N status. Nc Dilution Curves have been determined in several crops including summer maize on plant dry matter (DM) basis, yet no attempt has been made to determine the Nc Dilution Curve on the basis of leaf dry matter (LDM) in summer maize. The present study aimed to determine a Nc Dilution Curve based on LDM for in-season assessment of crop N status in summer maize. Six field experiments were performed with four summer maize cultivars using varied N fertilizer rates ranging from 0 to 320 kg N ha−1. The leaf Nc Curve was described by the equation: Nc = 3.45LDM−0.22, when LDM ranged from 1.18 to 3.45 t ha−1. For LDM