Assessing the regional biogenic methanol emission from spring wheat during the growing season: A Canadian case study

Based on the 1965–2017 climate data of 18 meteorological stations in the Songliao Plain maize belt, the Coupled Model Intercomparision Project (CMIP5) data, and the 1998–2017 maize yield data, the drought change characteristics in the study area were analyzed by using the standardized precipitation evapotranspiration index (SPEI) and the Mann–Kendall mutation test; furthermore, the relationship between meteorological factors, drought index, and maize climate yield was determined. Finally, the maize climate yields under 1.5 °C and 2.0 °C global warming scenarios were predicted. The results revealed that: (1) from 1965 to 2017, the study area experienced increasing temperature, decreasing precipitation, and intensifying drought trends; (2) the yield of the study area showed a downward trend from 1998 to 2017. Furthermore, the climate yield was negatively correlated with temperature, positively correlated with precipitation, and positively correlated with SPEI-1 and SPEI-3; and (3) under the 1.5 °C and the 2.0 °C global warming scenarios, the temperature and the precipitation increased in the maize growing season. Furthermore, under the studied global warming scenarios, the yield changes predicted by multiple regression were −7.7% and −15.9%, respectively, and the yield changes predicted by one-variable regression were −12.2% and −21.8%, respectively.

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High ear number is key to achieving high wheat yields in the high-rainfall zone of south-western Australia

Australian Journal of Agricultural Research ◽

10.1071/ar05170 ◽

2007 ◽

Vol 58 (1) ◽

pp. 21 ◽

Cited By ~ 18

Author(s):

Heping Zhang ◽

Neil C. Turner ◽

Michael L. Poole ◽

Senthold Asseng

Keyword(s):

Western Australia ◽

Spring Wheat ◽

Harvest Index ◽

Dry Matter ◽

Growing Season ◽

Growth And Yield ◽

Yield Potential ◽

Dry Matter Accumulation ◽

High Rainfall ◽

Sink Capacity

The growth and yield of spring wheat (Triticum aestivum L.) were examined to determine the actual and potential yields of wheat at a site in the high rainfall zone (HRZ) of south-western Australia. Spring wheat achieved yields of 5.5−5.9 t/ha in 2001 and 2003 when subsurface waterlogging was absent or minimal. These yields were close to the estimated potential, indicating that a high yield potential is achievable. In 2002 when subsurface waterlogging occurred early in the growing season, the yield of spring wheat was 40% lower than the estimated potential. The yield of wheat was significantly correlated with the number of ears per m2 (r2 = 0.81) and dry matter at anthesis (r2 = 0.73). To achieve 5–6 t/ha of yield of wheat in the HRZ, 450–550 ears per m2 and 10–11 t/ha dry matter at anthesis should be targetted. Attaining such a level of dry matter at anthesis did not have a negative effect on dry-matter accumulation during the post-anthesis period. The harvest index (0.36−0.38) of spring wheat was comparable with that in drier parts of south-western Australia, but relatively low given the high rainfall and the long growing season. This relatively low harvest index indicates that the selected cultivar bred for the low- and medium-rainfall zone in this study, when grown in the HRZ, may have genetic limitations in sink capacity arising from the low grain number per ear. We suggest that the yield of wheat in the HRZ may be increased further by increasing the sink capacity by increasing the number of grains per ear.

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Yield response of potatoes to variable nitrogen management by landform element and in relation to petiole nitrogen – A case study

Canadian Journal of Plant Science ◽

10.4141/cjps2011-005 ◽

2012 ◽

Vol 92 (4) ◽

pp. 771-781 ◽

Cited By ~ 7

Author(s):

A. P. Moulin ◽

Y. Cohen ◽

V. Alchanatis ◽

N. Tremblay ◽

K. Volkmar

Keyword(s):

Sandy Loam ◽

Growing Season ◽

Potato Yield ◽

Nitrogen Management ◽

N Fertilizer ◽

Yield Response ◽

Fertilizer Treatment ◽

Marketable Yield ◽

N Concentration

Moulin, A. P., Cohen, Y., Alchanatis, V., Tremblay, N. and Volkmar, K. 2012. Yield response of potatoes to variable nitrogen management by landform element and in relation to petiole nitrogen – A case study. Can. J. Plant Sci. 92: 771–781. Recent increases in the cost of fertilizer N have prompted producers to assess the potential to vary inputs within fields and during the growing season to produce the highest marketable yield of potatoes (Solanum tuberosum L.). A study was conducted from 2005 to 2007 near Brandon, Manitoba, Canada, to assess the spatial variability of potato yield in upper, middle and lower landform elements on a sandy loam soil in response to a range of N fertilizer rates applied in the spring or in combination with an application during the growing season. There was no clear trend with respect to the effect of landform on potato yield. Nitrogen fertilizer increased total and marketable yield relative to the control at rates from 75 to 225 kg ha−1in split applications or applied at seeding. No significant interaction between landform and fertilizer treatment was observed. Petiole N concentration, determined late in the growing season, was correlated with potato yield though the correlation varied considerably between years. Petiole leaflet N concentration was affected by fertilizer on most sampling dates, but decreased with time during the growing season. We conclude that although N fertilizer could be applied during the growing season based on petiole leaflet N concentration deficiencies in mid-July, there is no clear difference in potato yield due to split application relative to spring applications of N fertilizer at rates of 75 kg ha−1or greater based on landform elements for potato production, likely due to the short growing season in western Canada.

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The measurement of labour productivity: a case study.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v12i4.17514 ◽

1964 ◽

Vol 12 (4) ◽

pp. 281-290

Author(s):

H.A. Luning

Keyword(s):

Population Density ◽

Crop Production ◽

Labour Productivity ◽

Growing Season ◽

Northern Nigeria ◽

High Population Density ◽

Marginal Productivity ◽

General Survey ◽

Approach Zero

A case study is presented on labour productivity of 30 farmers living in a village in Northern Nigeria, a region with a relatively high population density of 500-600 persons per square mile. An adult male worker can provide the labour needs of about 4.5 acres of farm land during the growing season, but in this village only 1.5 acres per worker was available. An initial estimation of labour productivity, based on a general survey, led to the conclusion that marginal productivity approached zero. However, this conclusion appears to be erroneous, as a consequence of incorrect assessment of time spent on actual crop production by farmers. According to a detailed investigation on five farms, the number of man days per acre spent on crop production was remarkably uniform - about 19 man days per acre regardless of size of holding. This, in connection with other evidence, suggests that the marginal productivity of labour in this village is not zero and does not even approach zero. However, the availability of non-farm employment in the region may be of influence in this respect. R. V. H. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Reflections on the UNCRC’s Future from a Transdisciplinary Bricoleur

The International Journal of Children s Rights ◽

10.1163/15718182-02103002 ◽

2013 ◽

Vol 21 (3) ◽

pp. 510-522 ◽

Cited By ~ 4

Author(s):

Richard C. Mitchell

Keyword(s):

Theoretical Analysis ◽

Lived Experiences ◽

Final Section ◽

Growing Season ◽

Wine Industry ◽

Agricultural Workers ◽

Local Application ◽

The Cross ◽

Methodological Reflection

The paper argues two main points. First, there remain vast untapped potentials for implementing children’s rights within both present and coming generations, and second, that transdisciplinary theorising and local application can create and exploit such new opportunities. The paper begins with a theoretical analysis of the cross-cutting nature of the UNCRC, and its continued civilising impact as part of the globalised ‘rights revolutions’ reported by controversial Harvard psychologist Steven Pinker (2011: 378-481). I then move to a methodological reflection on how the treaty might be applied as a bricoleur in the lived experiences of children, families, caregivers and communities. The final section outlines a case study from the grape and wine industry located within the Niagara Region of Canada that applied these theoretical and methodological resources as a form of critical praxis in the lives of migrant agricultural workers temporarily employed there through the growing season year after year.

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Anthropogenic vegetation transformation and the potential for deep convection on the Canadian prairies

Canadian Journal of Soil Science ◽

10.4141/s98-011 ◽

1998 ◽

Vol 78 (4) ◽

pp. 657-666 ◽

Cited By ~ 26

Author(s):

R. L. Raddatz

Keyword(s):

Spring Wheat ◽

Deep Convection ◽

Global Radiation ◽

Bowen Ratio ◽

Growing Season ◽

Perennial Grasses ◽

Climatic Zone ◽

Canadian Prairie ◽

Canadian Prairies ◽

Field Crops

Widespread agricultural cultivation has converted nearly 60% of the Canadian Prairie grasslands eco-climatic zone from native mixed perennial grasses to annual field crops, predominantly spring wheat. This study examined the effect this anthropogenic landscape transformation has had on the partitioning of latent and sensible heat. For each type of vegetation, a representative growing-season Bowen ratio curve, based on modelled evapotranspiration values, was determined for sample sites — Winnipeg, MB, in the transitional grassland, and Swift Current, SK, in the arid grassland. A relationship between the Bowen ratio, the noon global radiation and the change in the Lifted Index between morning and afternoon was used to asses how modifying the apportionment of surface heat flux may have changed the seasonal frequency and severity of thunderstorms. Prior to the emergence of annual crops, and again during their senescence and in the post-harvest period, Bowen ratios are generally higher (i.e., evapotranspiration rates are lower) than they would be if the Prairie grassland eco-climatic zone had remained a sea of perennial grasses. Thus, the available buoyant energy or the potential for deep convection has been reduced in these periods. Given similar atmospheric dynamic forcing and advection patterns, this change has likely reduced the frequency of thunderstorms during the early and the late portions of the growing season. In contrast, during rapid foliage expansion and seed production for spring wheat, and for similar annual field crops, Bowen ratios are generally lower (i.e., evapotranspiration rates are higher) than they would be without agriculture. Thus, the potential for deep convection has been enhanced in these periods. With similar dynamic and advection patterns, it is probable that thunderstorms are now more frequent in the middle of the growing season and increased available buoyant energy may have made them, on average, more severe. Key words: Agrometeorology, land-use change, thunderstorms

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Upscaling modelled crop yields to regional scale: A case study using DSSAT for spring wheat on the Canadian prairies

Canadian Journal of Soil Science ◽

10.4141/cjss-2014-076 ◽

2015 ◽

Vol 95 (1) ◽

pp. 49-61 ◽

Cited By ~ 9

Author(s):

Ted Huffman ◽

Budong Qian ◽

Reinder De Jong ◽

Jiangui Liu ◽

Hong Wang ◽

...

Keyword(s):

Climate Change ◽

Spring Wheat ◽

Input Data ◽

Crop Yields ◽

Regional Scale ◽

Climate Change Impacts ◽

Crop Productivity ◽

Canadian Prairies ◽

Crop Models

Huffman, T., Qian, B., De Jong, R., Liu, J., Wang, H., McConkey, B., Brierley, T. and Yang, J. 2015. Upscaling modelled crop yields to regional scale: A case study using DSSAT for spring wheat on the Canadian prairies. Can. J. Soil Sci. 95: 49–61. Dynamic crop models are often operated at the plot or field scale. Upscaling is necessary when the process-based crop models are used for regional applications, such as forecasting regional crop yields and assessing climate change impacts on regional crop productivity. Dynamic crop models often require detailed input data for climate, soil and crop management; thus, their reliability may decrease at the regional scale as the uncertainty of simulation results might increase due to uncertainties in the input data. In this study, we modelled spring wheat yields at the level of numerous individual soils using the CERES–Wheat model in the Decision Support System for Agrotechnology Transfer (DSSAT) and then aggregated the simulated yields from individual soils to regions where crop yields were reported. A comparison between the aggregated and the reported yields was performed to examine the potential of using dynamic crop models with individual soils in a region for the simulation of regional crop yields. The regionally aggregated simulated yields demonstrated reasonable agreement with the reported data, with a correlation coefficient of 0.71 and a root-mean-square error of 266 kg ha−1 (i.e., 15% of the average yield) over 40 regions on the Canadian prairies. Our conclusion is that aggregating simulated crop yields on individual soils with a crop model can be reliable for the estimation of regional crop yields. This demonstrated its potential as a useful approach for using crop models to assess climate change impacts on regional crop productivity.

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