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

1998 ◽  
Vol 78 (4) ◽  
pp. 657-666 ◽  
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

scholarly journals Correlation of the vegetation index (NDVI) and phytometric parameters at different stages of field crops development

2020 ◽  
Author(s):  
Yu.A. Gulyanov ◽  
Keyword(s):  
Spring Wheat ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Stem Elongation ◽  
Grain Filling ◽  
Growing Season ◽  
Practical Application ◽  
Field Crops ◽  
The Relationship

The main goal of our research was to identify the relationship between the normalized difference vegetation index (NDVI) and the area of assimilation surface (AS) of spring wheat crops during the growing season, as well as to develop practical application of the findings. Throughout the growing season, the area of assimilation surface of T. aestivum increases much faster than the vegetation index NDVI. The smallest AS (282.7 m2/ha), which corresponded to 0.01 units of the NDVI (calculated factor) was observed during the tillering stage. It reaches its maximum values – 331.7–406.1–383.7 m2/ha (1.20–1.47–1.39 times higher) from stem elongation to the end of flowering. During the grain filling and maturation, these values decrease to 336.2 m2/ha but still are 1.19 times higher than the initial ones.

Yield stability analysis of broadly adaptive triticale germplasm in southern and central Alberta, Canada, for industrial end-use suitability

2011 ◽  
Vol 91 (1) ◽  
pp. 125-135 ◽  
Author(s):  
A. Goyal ◽  
B. L. Beres ◽  
H. S. Randhawa ◽  
A. Navabi ◽  
D. F. Salmon ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Spring Wheat ◽  
Relative Yield ◽  
Yield Stability ◽  
Environment Interaction ◽  
Canadian Prairie ◽  
Canadian Prairies ◽  
Hard Red Spring Wheat ◽  
End Use ◽  
Triticosecale Wittmack

Goyal A., Beres, B. L., Randhawa, H. S., Navabi, A., Salmon, D. F. and Eudes, F. 2011. Yield stability analysis of broadly adaptive triticale germplasm in southern and central Alberta, Canada for industrial end-use suitability. Can. J. Plant Sci. 91: 125–135. Triticale (×Triticosecale Wittmack) is a cereal crop with high grain yield and biomass potential, which are traits desired in biorefinery processes that currently utilize wheat (Triticum aestivum). This study was conducted to evaluate the performance of introduced germplasm for its adaptability to selected Canadian prairie agroecosystems, and to benchmark both introduced and registered triticale lines against hard red spring wheat. To investigate the genotype×environment interaction effects on the performance of triticale genotypes, 30 genotypes (27 triticale; 3 hard red spring wheat) were grown in three environments for 3 yr (2005–2007) in southern and central Alberta, Canada. Variance due to genotypes, years, locations, and their interactions were studied by employing several stability analysis models. Site Regression Model (SREG) and GGE biplot analysis were conducted to rank the relative yield performance of cultivars and to identify stable genotypes. Triticale consistently produced higher grain and biomass than hard red spring wheat, but some lines were high in pentosan content, produced low test weight, and possessed unacceptable growing degree day requirements. However, several of the introduction lines displayed superior trait performance and high stability. Five advanced to “C” level registration testing with one subsequently recommended for registration. The results provide evidence that some of the global triticale germplasm are well-suited to the production environments of the Canadian prairies, and that triticale has potential to be the ideal cereal platform for future technological and biorefinery end-use applications.

USE OF AGRO-RESOURCE POTENTIAL OF GRAY FOREST SOILS OF UPPER VOLGA REGION

2020 ◽  
Keyword(s):  
Forest Soils ◽  
Perennial Grasses ◽  
Organic Fertilizers ◽  
Volga Region ◽  
Winter Rye ◽  
Resource Potential ◽  
Field Crops ◽  
Upper Volga ◽  
Gray Forest Soils ◽  
Winter Cereals

The results of long-term research on the influence of main indicators on their agro-resource potential are summarized on gray forest soils of the upper Volga region. For the conditions of the Vladimir Opolie, the probable yield of biomass and the main products of field crops were calculated at different coefficients ofphotosynthetic active radiation (FAR) use. Calculations of the main product yields are made taking into account the distribution of biomass to by-products and crop-root residues. For field crops of the studied crop rotations, the coefficients of precipitation utilization are estimated. They varied from 44 to 71%, depending on the crop rotation culture. On the slope of the southern exposure when cultivating winter cereals and perennial grasses, the main moisture losses were observed in the spring during snowmelt, when growing spring crops and potatoes, they were close in the autumn and spring periods. The sizes of moisture use by crops depending on the fertilizer systems for the creation of 1 C of grain units (g.u.) and from sub-arable layers are determined. In comparison with the liming background, the use of organic fertilizers reduced the water consumption coefficient from 9.6 to 8.5 mm/C g.u., their combination with a single dose of NPK - up to 7.3, and with a double dose - up to 6.8 mm / C g.u. Based on the amount of moisture used by crops, their possible yields are calculated. In spring crops, the amount of precipitation consumed (326-356 mm) corresponds to the use of 2.7-3% of the FAR and provides 54-60 C/ha of grain, in winter rye and wheat - about 4% of the FAR (yield 71-80 C/ha). In perennial grasses for 2 mowing, the moisture consumed is enough to use about 3% of the FAR., in potatoes -1.5%.

Statistical spring wheat yield forecasting for the Canadian prairie provinces

2009 ◽  
Vol 149 (6-7) ◽  
pp. 1022-1031 ◽  
Author(s):  
Budong Qian ◽  
Reinder De Jong ◽  
Richard Warren ◽  
Aston Chipanshi ◽  
Harvey Hill
Keyword(s):  
Spring Wheat ◽  
Wheat Yield ◽  
Canadian Prairie ◽  
Yield Forecasting ◽  
Prairie Provinces

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

2021 ◽  
pp. 117602
Author(s):  
Mengfan Cai ◽  
Chunjiang An ◽  
Christophe Guy ◽  
Chen Lu ◽  
Fereshteh Mafakheri
Keyword(s):  
Spring Wheat ◽  
Growing Season

scholarly journals Comparison of Aerodynamic, Bowen-Ratio, and Penman-Monteith Methods in Estimating Evapotranspiration of Oil Palm Plantation

Agromet ◽  
2018 ◽  
Vol 32 (1) ◽  
pp. 11
Author(s):  
Tania June ◽  
Ni Wayan Srimani Puspa Dewi ◽  
Ana Meijide
Keyword(s):  
Oil Palm ◽  
Economic Value ◽  
Global Radiation ◽  
Reference Method ◽  
Bowen Ratio ◽  
Ratio Method ◽  
Agricultural Commodity ◽  
Evapotranspiration Rate ◽  
Oil Palms

<p>Oil palm is one important agricultural commodity that has high economic value. Oil palm productivity is significantly influenced by its water use (needs). Measurement and estimation of oil palm evapotranspiration is needed for determination of its water needs. Various methods are available and this study compare three methods, consisting of aerodynamic, Bowen-Ratio and Penman-Monteith methods in analyzing water needs/use of oil palms plantation located in PTPN VI Jambi.  Peak of evapotranspiration rate occured in the afternoon around 13.00 and 14.00 local time. Bowen-Ratio method has higher estimation value of evapotranspiration than the other two methods. Ratio between evapotranspiration and global radiation of two and ten-years old oil palm plantations remain similar, around 47%. Penman Monteith method has the nearest estimation value to reference method (aerodynamic method) showed by the smallest RMSE value, 0.087 for two years oil palm and 0.157 for ten-years old oil palm.<strong> </strong></p>

scholarly journals PRODUCTIVITY OF PERENNIAL GRASSES AND MIXTURES WITH DIFFERENT SOWING DATES IN WESTERN SIBERIA

2020 ◽  
pp. 24-32
Author(s):  
V. A. Petruk
Keyword(s):  
Dry Matter ◽  
Crop Yields ◽  
Growing Season ◽  
Single Species ◽  
Field Studies ◽  
Perennial Grasses ◽  
First Year ◽  
Sowing Dates ◽  
Second Year ◽  
Sowing Period

The results of field studies for 2017 - 2019 are presented. yields of perennial grasses sown at different times of the growing season. Spring, summer, and winter sowing periods were compared. Alfalfa, clover, rump, and also their mixtures were sown in 2017 under the cover of barley. The value of the cover crop yield of spring and summer sowing periods did not differ significantly and amounted to 4-5 t / ha of absolutely dry matter. Winter barley crops have not formed. On average, over 2 years of use, the highest yields were observed in alfalfa-crust grass mixtures - 3.4 t / ha of absolutely dry matter. The lowest yield was obtained in the single-species seeding of the rump. Correspondingly, in the spring, summer and winter periods of sowing, the yield of rump was 1.6; 1.1 and 1.3 t / ha. With a late sowing period, the yield of perennial grasses is significantly lower compared to spring and summer. With winter sowing periods, the yield was the highest for grass stands of alfalfa and alfalfacrust grass mixture - 2.3 and 2.4 t / ha. It should be noted that in the second year of use, the yield by the sowing dates in single-species crops and grass mixtures is leveled. The winter crops of perennial grasses in the first year of use formed a low yield. Only in the second year (third year of life) the productivity of perennial grasses of winter sowing began to increase. Consequently, in the area under perennial grasses of the winter sowing period, during one growing season (the next year after sowing), the crop was not actually formed. Based on the data obtained, production can be recommended for spring and summer planting of perennial grasses under the cover of barley. The winter sowing period provides economically valuable crop yields only by the third year of life.

scholarly journals Understanding Land-Atmosphere-Climate Coupling from the Canadian Prairie Dataset

2018 ◽  
Author(s):  
Alan K Betts ◽  
Raymond L Desjardins
Keyword(s):  
Snow Cover ◽  
Diurnal Cycle ◽  
Radiative Forcing ◽  
Potential Temperature ◽  
Warm Season ◽  
Growing Season ◽  
Cold Season ◽  
Maximum Temperature ◽  
Canadian Prairie ◽  
Cloud Forcing

Analysis of the hourly Canadian Prairie data for the past 60 years has transformed our quantitative understanding of land-atmosphere-cloud coupling. The key reason is that trained observers made hourly estimates of opaque cloud fraction that obscures the sun, moon or stars, following the same protocol for 60 years at all stations. These 24 daily estimates of opaque cloud data are of sufficient quality that they can be calibrated against Baseline Surface Radiation Network data to give the climatology of the daily short-wave, longwave and total cloud forcing (SWCF, LWCF and CF). This key radiative forcing has not been available previously for climate datasets. Net cloud radiative forcing reverses sign from negative in the warm season to positive in the cold season, when reflective snow reduces the negative SWCF below the positive LWCF. This in turn leads to a large climate discontinuity with snow cover, with a systematic cooling of 10&deg;C or more with snow cover. In addition, snow cover transforms the coupling between cloud cover and the diurnal range of temperature. In the warm season, maximum temperature increases with decreasing cloud, while minimum temperature barely changes; while in the cold season with snow cover, maximum temperature decreases with decreasing cloud and minimum temperature decreases even more. In the warm season, the diurnal ranges of temperature, relative humidity, equivalent potential temperature and the pressure height of the lifting condensation level are all tightly coupled to opaque cloud cover. Given over 600 station-years of hourly data, we are able to extract, perhaps for the first time, the coupling between cloud forcing and the warm season imbalance of the diurnal cycle; which changes monotonically from a warming and drying under clear skies to a cooling and moistening under cloudy skies with precipitation. Because we have the daily cloud radiative forci, which is large, we are able to show that the memory of water storage anomalies, from precipitation and the snowpack, goes back many months. The spring climatology shows the memory of snowfall back through the entire winter, and the memory in summer goes back to the months of snowmelt. Lagged precipitation anomalies modify the thermodynamic coupling of the diurnal cycle to the cloud forcing, and shift the diurnal cycle of mixing ratio which has a double peak. The seasonal extraction of the surface total water storage is a large damping of the interannual variability of precipitation anomalies in the growing season. The large land-use change from summer fallow to intensive cropping, which peaked in the early 1990s, has led to a coupled climate response that has cooled and moistened the growing season, lowering cloud-base, increasing equivalent potential temperature, and increasing precipitation. We show a simplified energy balance of the Prairies during the growing season and its dependence on reflective cloud.

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