scholarly journals Reducing N Application by Increasing Plant Density Based on Evaluation of Root, Photosynthesis, N Accumulation and Yield of Wheat

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1080
Author(s):  
Xiangqian Zhang ◽  
Shizhou Du ◽  
Yunji Xu ◽  
Chengfu Cao ◽  
Huan Chen
Keyword(s):  
Leaf Area ◽  
Plant Density ◽  
Application Rate ◽  
N Recovery ◽  
Individual Plant ◽  
N Accumulation ◽  
N Application ◽  
Area Index ◽  
N Level ◽  
N Application Rate

(Aims) To clarify the mechanisms though which dense planting could alleviate the negative effect of the reducing N rate on yield, (Methods) an experiment with four nitrogen levels—0 (N0), 120 (N1), 180 (N2) and 240 (N3) kg N ha−1—and three plant densities—180 (D1), 240 (D2) and 300 (D3) × 104 basic seedlings ha−1—was conducted. (Results) Increasing plant density decreased the root length, root volume, root surface area and root tips of individual plant while it enhanced the aforementioned root traits in population. The chlorophyll content, photosynthetic rate, stomatal conductance and transpiration rate of the individual plants were decreased with the increase in plant density and enhanced with the increase in N level. The increasing density and N application rate enhanced the leaf area index, photosynthetic high-efficiency leaf area and canopy photosynthetically active radiation of population. N accumulation per plant was decreased with increasing density and was enhanced with an increasing N application level. Within the same N level, the N accumulation in the population, N production efficiency and N recovery efficiency were consistently D3 > D2 > D1. A high N application rate with high density was not conducive to improving the NR (nitrate reductase), GS (glutamine synthetase) and GOGAT (glutamate synthase) activities. The yield could be maintained as stable or improved if decreasing by 60 kg N ha−1 with increasing 60 × 104 basic seedlings ha−1 within the range of N application in this experiment. (Conclusions) These results indicated that the yield of wheat could be improved with less N application by adjusting the compensatory effects from the plant density in populations.

scholarly journals Optimizing nitrogen fertilizer amount for best performance and highest economic return of winter wheat under limited irrigation conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260379
Author(s):  
Pin Zhang ◽  
Yi-kang Qi ◽  
Hong-guang Wang ◽  
Jian-ning He ◽  
Rui-qi Li ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Aboveground Biomass ◽  
Harvest Index ◽  
Application Rate ◽  
N Accumulation ◽  
N Application ◽  
Area Index

Inappropriate water and fertilizer management can lead to unstable crop yields. Excessive fertilization can potentially cause soil degradation and nitrogen (N) leaching. The aim of this study was to explore the optimal N application rate on two wheat varieties with different nitrogen responding under limited water irrigation at three experimental sites in the Piedmont plain of the Taihang Mountains, China. A two-year field experiment was conducted to explore the effects of five N application rates (N0, N120, N180, N240, and N300) on winter wheat growth, leaf area index, aboveground biomass, grain yield, grain N accumulation, and net return. The results showed that N application rate significantly affected leaf area index, aboveground biomass, grain yield, and harvest index. Variety and variety × N rate interactions had a significant effect on few indicators. Compared with N0, N180 improved leaf area index, aboveground biomass, grain yield, and grain N accumulation. Compared with N240 and N300, N180 increased the harvest index and N harvest index, without significantly reducing grain yield or grain N accumulation, while enhancing a higher N use efficiency. Fertilizers applied in the ranges of 144.7–212.9 and 150.3–247.0 kg ha-1 resulted in the highest net return for the KN199 and JM585 varieties, respectively. Our study provides a sound theoretical basis for high-efficiency fertilizer utilization in sustainable winter wheat production in the Piedmont plains of the Taihang Mountains of China.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 1. Appearance, expansion growth and life span of leaves of Brussels sprouts plants

1995 ◽  
Vol 43 (2) ◽  
pp. 217-232
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik
Keyword(s):  
Leaf Area ◽  
Application Rate ◽  
Leaf Number ◽  
N Application ◽  
Brussels Sprouts ◽  
Leaf Emergence ◽  
N Application Rate ◽  
Pot Trials ◽  
Leaf Expansion Rate ◽  
Green Leaf Area

In greenhouse pot trials, Brussels sprouts cv. Icarus SG2004 plants were supplied with various amounts of N at different stages during growth. The rate of leaf emergence ranged from 0.39 to 0.72 per day and was significantly increased by increasing N application rate. Leaf expansion rate and mature leaf area increased with leaf number, reaching maximum values between leaf number 10 and 20 and decreasing subsequently. Plants receiving more N had a higher total green leaf area per plant, due to more and larger green leaves. Specific leaf area of all leaves declined gradually from 130-230 cmsuperscript 2/g (depending on experiment) at about 30 days after planting to 60 cmsuperscript 2/g at the end of the experiments and was usually significantly increased by increasing N application rate.

scholarly journals How Does Nitrogen Application Rate Affect Plant Functional Traits and Crop Growth Rate of Perennial Ryegrass-Dominated Permanent Pastures?

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2499
Author(s):  
Tammo Peters ◽  
Friedhelm Taube ◽  
Christof Kluß ◽  
Thorsten Reinsch ◽  
Ralf Loges ◽  
...  
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Functional Traits ◽  
Perennial Ryegrass ◽  
N Uptake ◽  
Application Rate ◽  
Plant Functional Traits ◽  
N Application ◽  
Crop Growth Rate ◽  
N Application Rate

High doses of nitrogen (N) fertiliser input on permanent pastures are crucial in terms of N surplus and N losses. Quantitative analyses of the response of plant functional traits (PFT) driving crop growth rate (CGR) under low N input are lacking in frequently defoliated pastures. This study aimed to understand the significance of PFTs for productivity and N uptake in permanent grasslands by measuring dynamics in tiller density (TD), tiller weight (TW), leaf weight ratio (LWR), leaf area index (LAI), specific leaf area (SLA), as well as leaf N content per unit mass (LNCm) and per unit area (LNCa) in perennial ryegrass (Lolium perenne)-dominated pastures, in a simulated rotational grazing approach over two consecutive growing seasons. Annual N application rates were 0, 140 and 280 kg N ha−1. The phenological development of perennial ryegrass was the main driver of CGR, N uptake and most PFTs. The effect of N application rate on PFTs varied during the season. N application rate showed the greatest effect on TD, LAI and, to a lesser extent, on SLA and LNCm. The results of this study highlight the importance of TD and its role in driving CGR and N uptake in frequently defoliated permanent pastures.

scholarly journals Effect of nitrogen availability on dry matter production, nitrogen uptake and light interception of Brussels sprouts and leeks

1996 ◽  
Vol 44 (1) ◽  
pp. 3-19
Author(s):  
R. Booij ◽  
A.D.H. Kreuzer ◽  
A.L. Smit ◽  
A. Van Der Werf
Keyword(s):  
Leaf Area ◽  
N Uptake ◽  
Application Rate ◽  
N Application ◽  
Brussels Sprouts ◽  
N Concentration ◽  
N Application Rate ◽  
Leaf Area Expansion ◽  
Area Expansion ◽  
The Relationship

In field experiments with Brussels sprouts (cv. Kundry) and leeks (cv. Arcona) on a sandy soil, DM production and N uptake during crop growth were studied at different N application rates. N fertilizer application rate affected DM production, leaf area expansion and N uptake more strongly in Brussels sprouts than in leeks. When all N was applied before transplanting, Brussels sprouts showed a higher recovery of N fertilizer than leeks. This was explained by a higher rate of DM production in Brussels sprouts, a consequence of faster leaf area expansion. Late N application, whether as a part of a split application or not, increased N uptake more than DM production, so that tissue N concentrations increased. The relationship between N uptake and DM production depended on N availability and crop growth stage, and if all N was applied before transplanting, the relationship could be described by an asymptotic function. Plant plasticity allowed 'luxury consumption' of N to take place when availability was ample and 'dilution' of N when shortages developed during later growth stages. This implied an increasing tissue N concentration with increasing N application and a decreasing N concentration with increasing age. To achieve near-maximum DM production at any time, tissue N concentration should be kept at 2.8-3.1% DW during the whole growing period for Brussels sprouts as well as for leeks. However, in Brussels sprouts a minimum concentration of 1.2-1.5% DW still allowed growth. In both crops N uptake increased linearly with LAI until maximum leaf area (LAI = 4-5) was reached and this relationship was not affected by N application rate or by experimental year. Irrespective of N application rate or species, 2.3 g above ground biomass per MJ intercepted radiation was produced. Therefore, measurement of radiation interception by the canopy can be used as a tool to estimate the N status of the crop.

Evaluation of Makarikari grasses - potential production, nitrogen content and nitrogen recovery of two cultivars fertilized with urea

1974 ◽  
Vol 14 (66) ◽  
pp. 38 ◽  
Author(s):  
DL Lloyd
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
Application Rate ◽  
N Recovery ◽  
N Application ◽  
Spring Ephemerals ◽  
Application Rates ◽  
N Application Rate ◽  
Red Earth ◽  
N Use

Makarikari grass (Panicum coloratum var. makarikariense) cvs, 04634 and Bambatsi were fertilized with eight rates of urea (0-900 kg N ha-1 yr-1) under irrigation on a red earth at Toowoomba, and cut either 8-weekly or at full flower. Dry matter (D.M.) production increased linearly with N applications up to 450 kg ha-1 for both cultivars. Due to differences in growth rhythm between cultivars, 04634 produced higher total yields cut at full flower (29500 kg ha-1 yr-1) than at 8-weekly intervals (23100 kg ha-1 yr-1), whereas Bambatsi yielded similarly (23000 kg ha-1 yr-1) for the two cutting frequencies. Lower tissue N concentrations occurred at full flower than in 8-week growth for both cultivars (Q4634 -0.85 per cent to 1.08 per cent; Bambatsi-1.39 per cent to 1.55 per cent at 450 kg N ha-1). The N uptake by 04634 was the same for both cutting frequencies, but lower in Bambatsi cut at full flower. The association between N application rate, tissue N concentration and N uptake is outlined. The maximum efficiencies of both N use for D.M. production and per cent N recovery for 04634 and Bambatsi (55 and 35 kg D.M. per kg N applied; 40 and 60 per cent N recovery, respectively) were comparable with published values for other species. Increasing N application rates decreased the efficiency of D.M. production of both cultivars, decreased the per cent N recovery of Bambatsi, but had no effect on the per cent N recovery of 04634. In an extension of the Bambatsi study, the intrusion of spring ephemerals, mainly Bromus unioloides, did not reduce total D.M. production greatly and distributed it better through the growing season. Productivity of Bambatsi during mid-summer was not affected by prior weed competition in the spring.

Effects of plant density and inorganic nitrogen fertilizer on field beans (Vicia faba)

1995 ◽  
Vol 125 (1) ◽  
pp. 87-93 ◽  
Author(s):  
C. Aguilera-Diaz ◽  
L. Recalde-Manrique
Keyword(s):  
Vicia Faba ◽  
Seed Yield ◽  
Plant Density ◽  
Inorganic Nitrogen ◽  
Weather Conditions ◽  
Application Rate ◽  
Area Index ◽  
N Application Rate ◽  
Plant Densities ◽  
The Mean

SUMMARYA factorial experiment on Vicia faba L. cv. Alameda with three plant densities at three levels of nitrogen fertilization was done for three years (1984–87) at Granada. Yield varied markedly from 403 to 579 g/m2 between seasons. The mean increase in plant population density from 10 to 16 plants/m2 raised seed yield, but a further increase to 21 plants/m2 did not increase yield significantly. There was, however, considerable variation in the response to increasing density (Dl to D3) within each N level (N0, N1 and N2). Application of 30 kg N/ha at the start of flowering increased mean seed yield only at the lowest plant density and in 1986, but 60 kg N/ha increased yield by 135% on average over the 3 years. The highest N application rate resulted in consistently higher overall yields at each plant density. Leaf area index (LAI) showed a significant increase at 20 seeds/m2 compared with that at 10 seeds/m2 but there was no further increase at 30 seeds/m2. Harvest index (HI) was mainly affected by the annual weather conditions, and ranged from 47–4 in 1986 to 62–6 in 1987. HI was related to the mean temperature at flowering (April).

scholarly journals Optimizing plant density and nitrogen application to manipulate tiller growth and increase grain yield and nitrogen-use efficiency in winter wheat

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6484 ◽  
Author(s):  
Dongqing Yang ◽  
Tie Cai ◽  
Yongli Luo ◽  
Zhenlin Wang
Keyword(s):  
Grain Yield ◽  
Nitrogen Use Efficiency ◽  
Plant Density ◽  
Application Rate ◽  
Nitrogen Use ◽  
N Application ◽  
N Application Rate ◽  
Significant Difference ◽  
Plant Densities ◽  
Use Efficiency

The growth of wheat tillers and plant nitrogen-use efficiency (NUE) will gradually deteriorate in response to high plant density and over-application of N. Therefore, in this study, a 2-year field study was conducted with three levels of plant densities (75 ×104plants ha−1, D1; 300 ×104plants ha−1, D2; 525 ×104plants ha−1, D3) and three levels of N application rates (120 kg N ha−1, N1; 240 kg N ha−1, N2; 360 kg N ha−1, N3) to determine how to optimize plant density and N application to regulate tiller growth and to assess the contribution of such measures to enhancing grain yield (GY) and NUE. The results indicated that an increase in plant density significantly increased the number of superior tillers and the number of spikes per m2(SN), resulting in a higher GY and higher partial factor productivity of applied N (PFPN). However, there was no significant difference in GY and PFPNbetween plant densities D2 and D3. Increasing the N application rate significantly increased the vascular bundle number (NVB) and area (AVB), however, excess N application (N3) did not significantly improve these parameters. N application significantly increased GY, whereas there was a significant decrease in PFPNin response to an increase in N application rate. The two years results suggested that increasing the plant density (from 75 ×104plants ha−1to 336 ×104plants ha−1) in conjunction with the application of 290 kg N ha−1N will maximize GY, and also increase PFPN(39.7 kg kg−1), compared with the application of 360 kg N ha−1N. Therefore, an appropriate combination of increased planting density with reduced N application could regulate tiller number and favor the superior tiller group, to produce wheat populations with enhanced yield and NUE.

scholarly journals Nitrogen Leaching and Nitrogen Balance under Differing Nitrogen Fertilization for Sugarcane Cultivation on a Subtropical Island

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 740
Author(s):  
Ken Okamoto ◽  
Shinkichi Goto ◽  
Toshihiko Anzai ◽  
Shotaro Ando
Keyword(s):  
N Uptake ◽  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilizer ◽  
N Leaching ◽  
N Recovery ◽  
N Application ◽  
Fertilizer Application Rate ◽  
Sugarcane Yield ◽  
Cropping Seasons

Fertilizer application during sugarcane cultivation is a main source of nitrogen (N) loads to groundwater on small islands in southwestern Japan. The aim of this study was to quantify the effect of reducing the N fertilizer application rate on sugarcane yield, N leaching, and N balance. We conducted a sugarcane cultivation experiment with drainage lysimeters and different N application rates in three cropping seasons (three years). N loads were reduced by reducing the first N application rate in all cropping seasons. The sugarcane yields of the treatment to which the first N application was halved (T2 = 195 kg ha−1 N) were slightly lower than those of the conventional application (T1 = 230 kg ha−1 N) in the first and third seasons (T1 = 91 or 93 tons ha−1, T2 = 89 or 87 tons ha−1). N uptake in T1 and T2 was almost the same in seasons 1 (186–188 kg ha−1) and 3 (147–151 kg ha−1). Based on the responses of sugarcane yield and N uptake to fertilizer reduction in two of the three years, T2 is considered to represent a feasible fertilization practice for farmers. The reduction of the first N fertilizer application reduced the underground amounts of N loads (0–19 kg ha−1). However, application of 0 N in the first fertilization would lead to a substantial reduction in yield in all seasons. Reducing the amount of N in the first application (i.e., replacing T1 with T2) improved N recovery by 9.7–11.9% and reduced N leaching by 13 kg ha−1. These results suggest that halving the amount of N used in the first application can improve N fertilizer use efficiency and reduce N loss to groundwater.

scholarly journals A Plant Process Economic Model for Weed Management Decisions in Irrigated Onion

1999 ◽  
Vol 124 (1) ◽  
pp. 99-105 ◽  
Author(s):  
Claudio M. Dunan ◽  
Philip Westra ◽  
Frank D. Moore
Keyword(s):  
Leaf Area ◽  
Plant Density ◽  
Light Extinction ◽  
Species Number ◽  
Yield Reduction ◽  
Weed Species ◽  
Early Application ◽  
Area Index ◽  
Variable Approach ◽  
Number Of Leaves

A simulation model was built as a decision aid for management of five weed species in direct seeded irrigated onion (Allium cepa L.). The model uses the state variable approach and simulations are driven by temperature and sunlight as photosynthetically active radiation (PAR). It predicts yield reduction caused by competition for PAR according to the ratio of crop leaf area index (LAI) to weed LAI and respective light extinction coefficients (k). Input variables are plant density by species and average number of leaves by species. Number of leaves per plant is used by the model to provide an estimate of initial leaf area per plant. The model calculates initial species LAIs by multiplying species density times average leaf area per plant. The model accurately describes competitive interactions, taking into account respective plant densities, time of emergence, and time of weed removal. It permits economic evaluation of management factors such as handweeding, chemical weed control, herbicide phytotoxicity due to early application, and control of weed flushes during the season. The model is also used to evaluate mechanisms of plant competition for sunlight. In a sensitivity analysis, onion yield loss was more sensitive to weed PAR interception than to PAR use efficiency, the latter a species-dependent constant in the model.

scholarly journals AVALIAÇÃO DE TRÊS MÉTODOS DE OBTENÇÃO DO ÍNDICE DE ÁREA FOLIAR PARA CULTURA DA SOJA

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 284
Author(s):  
Ana Laura Pereira Souza ◽  
Marcelo Marques Costa ◽  
Darly Geraldo de Sena Junior ◽  
Rogério Borges de Oliveria Paz
Keyword(s):  
Leaf Area ◽  
Plant Density ◽  
Digital Images ◽  
Block Design ◽  
Linear Equations ◽  
Density Variation ◽  
Imaging Method ◽  
Area Index ◽  
Soybean Crop ◽  
Randomized Block Design

O Índice de área foliar (IAF) representa a eficiência na interceptação e utilização da radiação solar pelas plantas. O IAF pode ser obtido de forma direta, determinando-se a área foliar e área ocupada pela planta. Entretanto, métodos indiretos são comumente utilizados para sua estimativa devido a necessidade de praticidade. O objetivo deste trabalho foi avaliar a equivalência das estimativas do IAF obtidas por meio de um ceptômetro, pelo método de discos e utilizando imagens digitais. Para tanto, foi conduzido um experimento com a cultura da soja, no delineamento em blocos casualizados, com variação da densidade de plantas, para comparar os valores de IAF obtidos pelos diferentes métodos aos 34 dias após a semeadura (DAS). A comparação foi feita por meio dos coeficientes de equações lineares ajustadas entre os resultados obtidos. O método do disco e do ceptômetro, apresentaram uma boa equivalência entre seus valores. Entretanto, o método que utiliza imagens superestimou o IAF, não apresentando uma boa equivalência de seus valores aos do método de discos e ao ceptômetro.Palavras-chave: ceptômetro, discos foliares, imagens digitais. EVALUATION OF THREE OBTAINMENT METHODS OF FOLIAR AREA INDEX FOR SOYBEAN CROP ABSTRACT:The leaf area index (LAI) represents the interception efficiency and use of solar radiation by plants. IAF can be obtained directly, determining the leaf area and area occupied by the plant. However, indirect methods are commonly used for their estimation because for practicality. The objective of this work was to evaluate the equivalence of the LAI estimates obtained with a ceptometer, using the disc method and digital images. A experiment was conducted with soybean crop, in a randomized block design with plant density variation to compare the LAI values obtained by the different methods at 34 days after sowing (DAS). The comparison was made through the coefficients of linear equations adjusted between the results obtained. The disc and the ceptometer method presented a good equivalence between their values. However, the imaging method overestimated the LAI, not presenting a good equivalence of its values to those of the disc method and the ceptometer.Keywords: ceptometer, leaf discs, digital images.

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