scholarly journals Vegetative nitrogen stress decreases lodging risk and increases yield of irrigated spring wheat in the subtropics

2016 ◽  
Vol 67 (9) ◽  
pp. 907 ◽  
Author(s):  
A. S. Peake ◽  
K. L. Bell ◽  
P. S. Carberry ◽  
N. Poole ◽  
S. R. Raine
Keyword(s):  
Spring Wheat ◽  
Growth Phase ◽  
Vegetative Growth ◽  
Yield Potential ◽  
N Application ◽  
Area Index ◽  
Wheat Production ◽  
Small Plot ◽  
Management Techniques ◽  
Irrigated Wheat

In-crop nitrogen (N) application is used widely in rainfed winter wheat production to reduce lodging risk; however, uncertainty exists as to its ability to reduce lodging risk in subtropical irrigated wheat production without simultaneously reducing yield potential. The objective of this study was therefore to determine whether in-crop N application reduces lodging risk without reducing yield of irrigated spring wheat in a subtropical environment. Irrigated small-plot experiments were conducted to compare the effect of alternative N timing on lodging and yield in two cultivars. Variable N regimes were imposed during the vegetative growth phase, after which additional N was applied to ensure that total season N application was uniform across N-timing treatments. Treatments with low N at sowing had significantly less lodging and were the highest yielding, exhibiting yield increases of up to 0.8 t ha–1 compared to treatments with high N at sowing. Increased leaf area index, biomass and tiller count at the end of the vegetative growth phase were correlated with increased lodging in both cultivars, although the strength of the correlation varied with cultivar and season. We conclude that canopy-management techniques can be used to simultaneously increase yield and decrease lodging in irrigated spring wheat in the subtropics, but require different implementation from techniques used in temperate regions of Australia.

scholarly journals Impact of environmental changes and land-management practices on wheat production in India

2020 ◽  
Author(s):  
Shilpa Gahlot ◽  
Tzu-Shun Lin ◽  
Atul K. Jain ◽  
Somnath Baidya Roy ◽  
Vinay K. Sehgal ◽  
...  
Keyword(s):  
Land Management ◽  
Spring Wheat ◽  
Water Demand ◽  
Management Practices ◽  
Assessment Model ◽  
Nitrogen Fertilizers ◽  
Scale Production ◽  
Gangetic Plain ◽  
Area Index ◽  
Wheat Production

Abstract. Spring wheat is a major food crop that is a staple for a large number of people in India and the world. To address the issue of food security, it is essential to understand how productivity of spring wheat changes with changes in environmental conditions and agricultural management practices. The goal of this study is to quantify the role of different environmental factors and management practices on wheat production in India in recent years (1980 to 2016). Elevated atmospheric CO2 concentration ([CO2]) and climate change are identified as two major factors that represent changes in the environment. The addition of nitrogen fertilizers and irrigation practices are the two land-management factors considered in this study. To study the effects of these factors on wheat growth and production, we developed crop growth processes for spring wheat in India and implemented them in the Integrated Science Assessment Model (ISAM), a state-of-the-art land model. The model is able to capture site-level observed crop leaf area index (LAI) and country scale production. Numerical experiments are conducted with the model to quantify the effect of each factor on wheat production on a country scale for India. Our results show that elevated [CO2] levels, water availability through irrigation and nitrogen fertilizers have led to an increase in annual wheat production at 0.68, 0.24 and 0.31 Mt/yr, respectively, averaged over the time period 1980-2016. However, elevated temperatures have reduced the total wheat production at a rate of 0.37 Mt/yr during the study period. Overall, the [CO2], irrigation, fertilizers, and temperature forcings have led to 39 %, 15 %, 20 % and −16 % changes in countrywide production, respectively. The magnitudes of these factors spatially vary across the country thereby affecting production at regional scales. Results show that favourable growing season temperatures, moderate to high fertilizer application, high availability of irrigation facilities, and moderate water demand make the Indo-Gangetic plain the most productive region while the arid northwest region is the least productive due to high temperatures and lack of irrigation facilities to meet the high water demand.

scholarly journals Impact of environmental changes and land management practices on wheat production in India

2020 ◽  
Vol 11 (3) ◽  
pp. 641-652
Author(s):  
Shilpa Gahlot ◽  
Tzu-Shun Lin ◽  
Atul K. Jain ◽  
Somnath Baidya Roy ◽  
Vinay K. Sehgal ◽  
...  
Keyword(s):  
Land Management ◽  
Spring Wheat ◽  
Water Demand ◽  
Management Practices ◽  
Elevated Temperatures ◽  
Assessment Model ◽  
Nitrogen Fertilizers ◽  
Gangetic Plain ◽  
Area Index ◽  
Wheat Production

Abstract. Spring wheat is a major food crop that is a staple for a large number of people in India and the world. To address the issue of food security, it is essential to understand how the productivity of spring wheat varies with changes in environmental conditions and agricultural management practices. The goal of this study is to quantify the role of different environmental factors and management practices on wheat production in India in recent years (1980 to 2016). Elevated atmospheric CO2 concentration ([CO2]) and climate change are identified as two major factors that represent changes in the environment. The addition of nitrogen fertilizers and irrigation practices are the two land management factors considered in this study. To study the effects of these factors on wheat growth and production, we developed crop growth processes for spring wheat in India and implemented them in the Integrated Science Assessment Model (ISAM), a state-of-the-art land model. The model is able to simulate the observed leaf area index (LAI) at the site scale and observed production at the country scale. Numerical experiments are conducted with the model to quantify the effect of each factor on wheat production on a country scale for India. Our results show that elevated [CO2] levels, water availability through irrigation, and nitrogen fertilizers have led to an increase in annual wheat production at 0.67, 0.25, and 0.26 Mt yr−1, respectively, averaged over the time period 1980–2016. However, elevated temperatures have reduced the total wheat production at a rate of 0.39 Mt yr−1 during the study period. Overall, the [CO2], irrigation, fertilizers, and temperature forcings have led to 22 Mt (30 %), 8.47 Mt (12 %), 10.63 Mt (15 %), and −13 Mt (−18 %) changes in countrywide production, respectively. The magnitudes of these factors spatially vary across the country thereby affecting production at regional scales. Results show that favourable growing season temperatures, moderate to high fertilizer application, high availability of irrigation facilities, and moderate water demand make the Indo-Gangetic Plain the most productive region, while the arid north-western region is the least productive due to high temperatures and lack of irrigation facilities to meet the high water demand.

scholarly journals Simulating the Response of Drought–Tolerant Maize Varieties to Nitrogen Application in Contrasting Environments in the Nigeria Savannas Using the APSIM Model

Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Aloysius Beah ◽  
Alpha Y. Kamara ◽  
Jibrin M. Jibrin ◽  
Folorunso M. Akinseye ◽  
Abdullahi I. Tofa ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Production Systems ◽  
Agricultural Practices ◽  
Net Income ◽  
Nitrogen Application ◽  
N Application ◽  
Area Index ◽  
Support Tool ◽  
Maize Varieties

This paper assessed the application of the Agricultural Production Systems sIMulator (APSIM)–maize module as a decision support tool for optimizing nitrogen application to determine yield and net return of maize production under current agricultural practices in the Nigeria savannas. The model was calibrated for two maize varieties using data from field experiments conducted under optimum conditions in three locations during the 2017 and 2018 cropping seasons. The model was evaluated using an independent dataset from an experiment conducted under different nitrogen (N) levels in two locations within Southern and Northern Guinea savannas. The results show that model accurately predicted days to 50% anthesis and physiological maturity, leaf area index (LAI), grain yield and total dry matter (TDM) of both varieties with low RMSE and RMSEn (%) values within the range of acceptable statistics indices. Based on 31-year seasonal simulation, optimum mean grain yield of 3941 kg ha−1 for Abuja, and 4549 for Kano was simulated at N rate of 120 kg ha–1 for the early maturing variety 2009EVDT. Meanwhile in Zaria, optimum mean yield of 4173 kg ha–1 was simulated at N rate of 90 kg ha−1. For the intermediate maturing variety, IWDC2SYNF2 mean optimum yields of 5152, 5462, and 4849 kg ha−1, were simulated at N application of 120 kg ha−1 for all the locations. The probability of exceeding attainable mean grain yield of 3000 and 4000 kg ha−1 for 2009EVDT and IWDC2SYNF2, respectively would be expected in 95% of the years with application of 90 kg N ha−1 across the three sites. Following the profitability scenarios analysis, the realistic net incomes of US$ 536 ha–1 for Abuja, and US$ 657 ha−1 for Zaria were estimated at N rate of 90 kg ha−1 and at Kano site, realistic net income of US$ 720 ha–1was estimated at N rate of 120 kg ha−1 for 2009EVDT.For IWDC2SYNF2, realistic net incomes of US$ 870, 974, and 818 ha−1 were estimated at N application of 120 kg ha−1 for Abuja, Zaria, and Kano respectively. The result of this study suggests that 90 kg N ha−1 can be recommended for 2009EVDT and 120 kg N ha–1 for IWDC2SYNF2 in Abuja and Zaria while in Kano, 120 kg N ha−1 should be applied to both varieties to attain optimum yield and profit.

scholarly journals Combining Process Modelling and LAI Observations to Diagnose Winter Wheat Nitrogen Status and Forecast Yield

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 314
Author(s):  
Andrew Revill ◽  
Vasileios Myrgiotis ◽  
Anna Florence ◽  
Stephen Hoad ◽  
Robert Rees ◽  
...  
Keyword(s):  
Field Experiments ◽  
Process Models ◽  
Agricultural Technologies ◽  
N Application ◽  
Area Index ◽  
Complex Process ◽  
C Cycle ◽  
The Mean ◽  
Leaf N Content ◽  
Leaf N

Climate, nitrogen (N) and leaf area index (LAI) are key determinants of crop yield. N additions can enhance yield but must be managed efficiently to reduce pollution. Complex process models estimate N status by simulating soil-crop N interactions, but such models require extensive inputs that are seldom available. Through model-data fusion (MDF), we combine climate and LAI time-series with an intermediate-complexity model to infer leaf N and yield. The DALEC-Crop model was calibrated for wheat leaf N and yields across field experiments covering N applications ranging from 0 to 200 kg N ha−1 in Scotland, UK. Requiring daily meteorological inputs, this model simulates crop C cycle responses to LAI, N and climate. The model, which includes a leaf N-dilution function, was calibrated across N treatments based on LAI observations, and tested at validation plots. We showed that a single parameterization varying only in leaf N could simulate LAI development and yield across all treatments—the mean normalized root-mean-square-error (NRMSE) for yield was 10%. Leaf N was accurately retrieved by the model (NRMSE = 6%). Yield could also be reasonably estimated (NRMSE = 14%) if LAI data are available for assimilation during periods of typical N application (April and May). Our MDF approach generated robust leaf N content estimates and timely yield predictions that could complement existing agricultural technologies. Moreover, EO-derived LAI products at high spatial and temporal resolutions provides a means to apply our approach regionally. Testing yield predictions from this approach over agricultural fields is a critical next step to determine broader utility.

Biggar red spring wheat

1991 ◽  
Vol 71 (2) ◽  
pp. 519-522 ◽  
Author(s):  
R. M. DePauw ◽  
K. R. Preston ◽  
T. F. Townley-Smith ◽  
E. A. Hurd ◽  
G. E. McCrystal ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Triticum Aestivum L ◽  
Yield Potential ◽  
High Yield ◽  
Flour Milling ◽  
Wide Adaptation ◽  
Cultivar Description ◽  
End Use ◽  
Milling Properties

Biggar red spring wheat (Triticum aestivum L.) combines high grain yield potential with semidwarf stature and wide adaptation. Biggar has improved end-use suitability relative to HY320 such as harder kernels, better flour milling properties, greater water absorption, and stronger gluten properties. It received registration No. 3089 and is eligible for grades of Canada Prairie Spring (red). Key words: Triticum aestivum, wheat (spring), high yield, cultivar description

scholarly journals Effects of bromeliad flowering event on the community structuring of aquatic insect larvae associated with phytotelmata of Aechmea distichantha Lem. (Bromeliaceae)

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Felipe Emiliano Amadeo ◽  
Juliana Déo Dias ◽  
Bianca Trevizan Segovia ◽  
Nadson Ressyé Simões ◽  
Fábio Amodêo Lansac-Tôha
Keyword(s):  
Growth Phase ◽  
Vegetative Growth ◽  
Beta Diversity ◽  
Aquatic Insect ◽  
Insect Larvae ◽  
Local Factors ◽  
Flowering Phase ◽  
Regional Factors ◽  
Aquatic Insect Larvae ◽  
Phenological Phases

Abstract Aim: We aimed to understand how aquatic insect larvae communities associated with bromeliad phytotelmata are affected by plant architecture, predators and resources (local factors), and by geographical distance (regional factors) in two different plant phenological phases. Bromeliad flowering results in plant structural changes, which favours insect dispersal. Considering that local and regional factors may affect the community of aquatic insect larvae, we expected that composition, beta diversity and the importance of those factors would differ in the vegetative growth and flowering phases. Methods We performed six samplings of the bromeliad associated fauna in 2010, three during the first semester - vegetative growth phase - and three during the second semester - flowering phase. In each sampling, we collected 12 plants along the rocky walls with similar location distribution, with a total of 72 bromeliads studied. Results Although beta diversity (PERMDISP) did not differ between vegetative growth and flowering, NMDS followed by ANOSIM showed that composition was significantly different in the distinct phenological phases. IndVal results showed that three Diptera morphospecies were discriminant of the vegetative growth phase. In addition, pRDA revealed differences in the relative contribution of local and regional factors to explain insect larvae community structure. During the flowering phase, local factors predominated, while during vegetative growth, regional factors were more important. Conclusion Differences in dispersal rates between the two phenological phases, likely due to adult insect pollination and further oviposition, influenced community structuring. Therefore, flowering events account for differences not only in the composition, but also in community structuring of aquatic insect larvae inhabiting the phytotelmata of Aechmea distichantha Lem. (Bromeliaceae).

scholarly journals Elucidating the genetic basis of biomass accumulation and radiation use efficiency in spring wheat and its role in yield potential

2019 ◽  
Vol 17 (7) ◽  
pp. 1276-1288 ◽  
Author(s):  
Gemma Molero ◽  
Ryan Joynson ◽  
Francisco J. Pinera‐Chavez ◽  
Laura‐Jayne Gardiner ◽  
Carolina Rivera‐Amado ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Genetic Basis ◽  
Biomass Accumulation ◽  
Radiation Use Efficiency ◽  
Yield Potential ◽  
Use Efficiency ◽  
Radiation Use

scholarly journals Yield and vegetative growth of cactus pear at different spacings and under chemical fertilizations

2016 ◽  
Vol 20 (6) ◽  
pp. 564-569 ◽  
Author(s):  
João A. da Silva ◽  
Sérgio L. R. Donato ◽  
Paulo E. R. Donato ◽  
Evilasio dos S. Souza ◽  
Milton C. Padilha Júnior ◽  
...  
Keyword(s):  
Plant Growth ◽  
Plant Height ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Block Design ◽  
Plant Age ◽  
Cactus Pear ◽  
Area Index ◽  
Randomized Block Design

ABSTRACT The objective was to evaluate the effect of different spacings and mineral fertilizations on cactus pear growth and production in a randomized block design, with three replicates, in a 3 x 4 factorial scheme: three spacings, 1.00 x 0.50 m, 2.00 x 0.25 m and 3.00 x 1.00 x 0.25 m, and four fertilizations, 000-000-000, 000-150-000, 200-150-000 and 200-150-100 kg ha-1 of N, P2O5 and K2O, respectively. Plant growth was evaluated between 90 and 390 days and production and growth were evaluated at 620 days after planting. There were significant interactions between spacing and fertilization for plant height, number of cladodes and cladode area index from 90 to 390 days and for production of fresh and dry matter at 620 days after planting. Spacing influenced cladode area index, while fertilization influenced plant height, number of cladodes and cladode area index at 620 days after planting. Plant height showed cubic effect for the days after planting. Number of cladodes and cladode area index were dependent on spacing, fertilization and plant age, and fitted to cubic models. The best results of growth and production of fresh and dry matter are associated with NPK and NP fertilizations and the spacing of 1.00 x 0.50 m.

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